Category: News

Isohelix products have been used in a number of peer-reviewed papers on the oral microbiome.

In this blog, we discuss:

• The importance of the oral microbiome
• Sampling the oral microbiome
• How to sample the oral microbiome using whole saliva
• How to sample the oral microbiome using swabs

Introduction

The oral cavity is the second largest and most diverse microbial community in the body after the gut, and variations in the oral microbiome have been linked to numerous disorders (for a recent review see Tan et al (2024)).[i]  How a microbiome sample is collected and stored can change the observed diversity.

Sampling the oral microbiome

Several studies have shown differences in the observed oral microbiome, depending on the sampling method. For example, in 2022 Lee et al[ii] used real time PCR assays to determine ribosomal DNA (rDNA) copy numbers of 10 major oral microbes, comparing seven saliva and plaque collection methods. The study found that the microbial community found in saliva samples differs from that found in plaque.

A second 2022 study by Kaan et al[iii], found that tooth-associated taxa were underrepresented in saliva sampled using swabs. Spit saliva contains micro-organisms from multiple intra-oral surfaces, while swabbed saliva mainly contains micro-organisms from the sublingual mucosa.

If you are studying a particular niche within the oral cavity, for example the tongue, buccal mucosa or subgingival plaque, then use a site-targeted swab or curette. Smaller amounts of saliva can be sampled using swabs, but to sample the whole community within the oral cavity, saliva collected in a tube will give the greatest microbial diversity.

How to sample the oral microbiome using whole saliva

Saliva sampling is a straightforward and non-invasive method of collecting oral microbiome samples.

Isohelix have developed a kit specifically for collecting saliva for microbiomics, the GeneFiX™ Saliva Microbiome DNA Collector (MFX). The saliva collection device in the kit is pre-filled with stabilization buffer that stabilizes the microbial community from the moment of collection, for more than 12 months.

The kit is simple and easy to use – the donor simply spits into a specially designed collection funnel, and the saliva passes into a collection tube pre-filled with stabilization buffer. For the complete instructions for use, click here.

Several peer reviewed publications have used Isohelix  GeneFiX™ Saliva Microbiome DNA Collector (MFX) kits to study the oral microbiome – including the following:

• Bhanu, P., Buchke, S., Hemandhar-Kumar, N. et al. Comparative metagenomic analysis of the oral microbiome in COVID-19 patients and healthy individuals. Sci Rep 15, 10303 (2025). https://doi.org/10.1038/s41598-024-81864-3
  • “1ml saliva samples were collected using the GeneFiX™ Saliva Microbiome DNA Collector Kit and shipped at room temperature for RNA extraction. Long read whole genome sequencing of cDNA generated from the samples was performed to investigate microbial shifts associated with COVID-19.”

• Ostrowska, M.; Nowosad, K.; Mikoluc, B.; Szczerba, H.; Komon-Janczara, E. Changes in the Gut and Oral Microbiome in Children with Phenylketonuria in the Context of Dietary Restrictions—A Preliminary Study. Nutrients 2024, 16, 3915. https://doi.org/10.3390/nu16223915
  • “Saliva was collected into GeneFix™ Saliva Microbiome DNA Collector tubes and 16S rRNA gene sequencing was used to analyse microbial communities.”

• Alyousef, Y.M., Piotrowski, S., Alonaizan, F.A. et al. Oral microbiota analyses of paediatric Saudi population reveals signatures of dental caries. BMC Oral Health 23, 935 (2023). https://doi.org/10.1186/s12903-023-03448-3[RO4]
  • “Saliva was collected into GeneFix™ Saliva Microbiome DNA Collector tubes and bacterial DNA was extracted using the GeneFix Saliva DNA Extraction Kit. Oral microbiota composition and abundance were identified using 16 S rRNA sequencing .”

How to sample the oral microbiome using swabs

To discuss which sampling method would be best for your oral microbiome study, contact us at info@isohelix.com.

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[i] Tian S, Ding T, Li H. Oral microbiome in human health and diseases. mLife. 2024;3:367-383. https://doi.org/10.1002/mlf2.12136

[ii] Lee Y, Hong J, Lee G.  Composition and Diversity of Salivary Microbiome Affected by Sample Collection Method.  JOMP 2022;47:10-26.  https://doi.org/10.14476/jomp.2022.47.1.10

[iii] Kaan, A. M., Brandt, B. W., Buijs, M. J., Crielaard, W., Keijser, B. J., & Zaura, E. (2022). Comparability of microbiota of swabbed and spit saliva. European journal of oral sciences, 130 (2), e12858. https://doi.org/10.1111/eos.12858

Isohelix products have been used in a large number of peer-reviewed animal population genetics publications, supporting applications including conservation genomics, livestock breeding, biodiversity monitoring, veterinary genetics, and wildlife population studies.

In this blog, we discuss:

• The challenges faced by researchers collecting DNA samples in the field
• Key molecular biology techniques used for animal population genetics
• How to choose which Isohelix DNA sampling and extraction products to use for your animal population genetics study
• Some recent studies using Isohelix products to study a wide range of species, from large mammals to small invertebrates.

Introduction

For more information on how scientists are using Isohelix products to collect high-quality nucleic acid samples from a range of environments, such as jungles, deserts, and marine environments, see our blog, “How Researchers Use Isohelix Kits in Extreme Environments.”

Which molecular techniques are used to study animal population genetics?

As animal population genetics has evolved, researchers have moved from analyzing a handful of genetic markers using PCR-based methods to genome-wide approaches such as SNP microarrays and next-generation sequencing. The technique used depends on the biological question being asked, the species being studied, and the level of genomic resolution required.

The most commonly used molecular techniques for animal population genetics studies are:

• PCR-based genotyping – used to analyze a small number of genetic markers, e.g., microsatellites, species-specific markers, or SNPs. They are cost-effective and particularly useful for targeted studies in which researchers need to genotype large numbers of samples across a limited number of loci.
• SNP microarrays – Widely used in livestock breeding, conservation genetics, and population structure studies to analyze thousands to hundreds of thousands of genetic markers simultaneously across the genome. Provide a genome-wide view of genetic variation at relatively low cost.
• Next Generation Sequencing (NGS) – NGS technologies generate large-scale genomic datasets ranging from targeted gene panels to whole genomes. They provide the highest resolution for studying genetic diversity, adaptation, evolution, and population structure, and are increasingly becoming the standard approach for animal population genomics.
• Mitochondrial sequencing – Mitochondrial DNA (mtDNA) is inherited maternally and evolves relatively rapidly, making it useful for studying ancestry, population history, and species relationships.

DNA input requirements vary between platforms, library preparation kits, and laboratories. More demanding NGS applications generally require larger quantities of higher-quality DNA, making sample collection, stabilization, and extraction particularly important. In contrast, PCR  or mitochondrial sequencing can often tolerate smaller amounts of more degraded DNA.

How to choose which DNA sampling and extraction products to use for your animal population genetics study

With a range of products available for a number of different scenarios, it can be difficult to decide which products to use for your study.

The table below gives suggestions of which Isohelix products to use, in which circumstances:

Table 1: Isohelix Products for Animal Population Genetics Studies

Workflow Step	Typical Sample Type	Example Applications	Isohelix Product	Key Benefits
Sample collection	Buccal epithelial cells from larger animals, faecal surface swabs	Wildlife population genetics, livestock genomics, conservation studies, pedigree analysis	Isohelix Buccal Swabs	High DNA yield, easy field collection, suitable for medium-to-large animals
Sample collection	Buccal cells and from small animals	Buccal cells and from small animals Amphibians, reptiles, nestlings, bats, fish, insects and other small organisms	Isohelix Mini Swabs	Designed for small mouths and delicate sampling, minimises animal stress
Sample collection	Faecal surface swabs	Non-invasive wildlife population genetics, endangered species monitoring, carnivore and herbivore studies	Isohelix Xtreme DNA Kit	Optimised for challenging low-abundance DNA samples collected from faecal surfaces
Sample stabilisation	Buccal and surface swab samples	Stabilising DNA from remote wildlife studies, biodiversity surveys, international field projects	RapiDri Swab Kits	Integrated desiccant stabilisation enables dry, ambient-temperature storage and transport and reduces cross-contamination
Sample stabilisation	Buccal swabs and faecal surface swabs	Longitudinal population studies, conservation genomics, biobanking	BuccalFix Stabilisation Buffer	Preserves DNA at ambient temperature for up to two years
DNA Extraction	Buccal swabs, saliva and stabilised samples	SNP genotyping, microsatellite analysis, GWAS, population structure studies and sequencing workflows	Isohelix DNA Isolation Kits	Available in spin-column and precipitation formats, optimised for Isohelix collection systems

To discuss which products would be best for your study, drop us a line at info@isohelix.com

Recent Publications Using Isohelix Products to Study Animal Populations

Published research citing Isohelix products spans mammals, reptiles, birds, amphibians, and invertebrates across multiple continents.

Here are some recent examples of peer-reviewed studies that used Isohelix products.

For more publications featuring Isohelix products, please visit the publications page.

• Penguins:

Stanners, A., and A.McGaughran. 2026. “From Nest Box to Neighborhood: Patterns of Island Biodiversity Characterized Through eDNA From Little Blue Penguin (Eudyptula minor) Nest Boxes.” Environmental DNA8, no. 3: e70302. https://doi.org/10.1002/edn3.70302.

• Chameleons:

Koutsokali, M., Dianni, C. and Valahas, M. (2023), Buccal swabs as an effective alternative to traditional tissue sampling methods for DNA analyses in Chamaeleonidae. Wildlife Biology, 2023: e01052. https://doi.org/10.1002/wlb3.01052

• Freshwater mussels:

Perkins MA, DeVilbiss KL, Whelan NV, Hoch RA, Jones BK, Mays JW, Evans HK, Benfield SB (2025) A new endemic freshwater mussel (Bivalvia, Unionidae) genus and species, Ligodonta obscura, from the Yadkin-Pee Dee River drainage in North Carolina, USA. ZooKeys 1248: 245-265. https://doi.org/10.3897/zookeys.1248.152952

• Elephants:

Sinovas P, Smith C, Keath S, Chantha N, Kaden J, Ith S, Ball A. 2025. Giants in the landscape: status, genetic diversity, habitat suitability and conservation implications for a fragmented Asian elephant (Elephas maximus) population in Cambodia. PeerJ 13:e18932 https://doi.org/10.7717/peerj.18932

Genomic research is at the heart of efforts to understand, detect and treat cancer. From identifying hereditary risk variants to characterising tumour biology, the quality of genetic analysis depends on the quality of nucleic acid samples analysed.

Whether samples are collected in the lab or remotely, extracted nucleic acids must be able to support sensitive downstream applications such as genome-wide association studies (GWAS), next-generation sequencing (NGS) and epigenetic analyses.

Isohelix sample collection, stabilisation and extraction products have been designed to meet this challenge. Combining non-toxic, guanidinium-free chemistry with high-yield collection formats and a room-temperature storage capability of up to 60 months, Isohelix products are trusted by researchers around the world for their sample collection needs.

In this article, we present four studies where Isohelix products have been used for different aspects of cancer research:

• Identifying Breast Cancer Risk in Younger Women: The BCAN-RAY Study
• Expanding Access to BRCA Testing: The BRCA-DIRECT Study
• Oral Microbiome Disruption as a Marker of Oral Cancer
• Genomic Biomarkers of Chemoradiation Response in Cervical Cancer

Identifying Breast Cancer Risk in Younger Women: The BCAN-RAY Study

The Breast Cancer Risk Assessment in Younger Women (BCAN-RAY)[i] study began in May 2023. This ongoing study aims to evaluate a comprehensive breast cancer risk assessment strategy among a diverse ethnic and socioeconomic population of women aged 30–39 years, without a strong family history of breast cancer.

The study recruited 250 women previously diagnosed with breast cancer alongside 750 control participants aged 30–39 years. None of the participants had a strong family history of the disease.

Control participants complete questionnaires about breast cancer risk factors, undergo low-dose mammograms, and donate a saliva sample which is collected using Isohelix GeneFix Saliva Collection Kits. Saliva samples are used to analyse the genetic makeup of all participants and identify those at higher risk using a tool called a polygenic risk score, which is a powerful predictor of breast cancer risk.

Expanding Access to BRCA Testing: The BRCA-DIRECT Study

A second breast cancer study, the BRCA-DIRECT study[ii] aims to provide an easy way for patients with breast cancer to access genetic testing within the NHS, and examines the feasibility, safety, and acceptability of a digital information model.

Participants are then randomized to receive their results digitally or by booking a telephone appointment with a genetic counsellor. Everyone who has a positive result is then referred to their local clinical genetics team. If the digital pathway is successful, the concept could be expanded to other cancers and hospitals.

Oral Microbiome Disruption as a Marker of Oral Cancer

The oral microbiome is increasingly recognised as a potential biomarker for diseases including oral cancer. In the publication, “Differences in the bacteriome of swab, saliva, and tissue biopsies in oral cancer” (Gopinath et al 2021[iii]), researchers characterised the bacteriome of saliva, swab, and tissue biopsy samples.

The ability to detect cancer-associated microbiome signatures using saliva rather than tissue biopsy has obvious clinical potential. The non-invasive longitudinal monitoring of microbiome composition in high-risk patients could offer an early warning system for malignant progression without the need for repeated invasive procedures.

Genomic Biomarkers of Chemoradiation Response in Cervical Cancer

In the final featured study, by Nolasco et al[iv] (2025), genomic changes were investigated as biomarkers of chemoradiation therapy response in locally advanced cervical cancer.

Locally advanced cervical cancer is typically treated with concurrent chemoradiation therapy (CRT), but clinical responses vary considerably between patients. Identifying genomic biomarkers that can predict or monitor treatment response would enable clinicians to personalise care and potentially intervene earlier in patients who are not responding as expected.

This study exemplifies a rapidly growing application area for non-invasive DNA collection: serial sampling across the course of treatment. Isohelix GeneFix™ devices stabilise DNA immediately upon collection and require no cold storage, so the same participant can donate samples at multiple time points, in the clinic, at home, or at a local collection point, without compromising sample quality. This longitudinal flexibility is increasingly important as cancer research moves toward real-time monitoring of treatment response.

Why Researchers Choose Isohelix for Cancer Genomics

As cancer genomics continues to evolve towards larger cohorts, more sensitive assays, longitudinal monitoring, and increasingly personalised treatment decisions, the need for reliable, accessible, and scalable sample collection solutions continues to grow.

Across each of these studies, Isohelix products provided reliable, high-quality DNA and RNA samples enabling cancer researchers to generate meaningful results.

Several features make Isohelix particularly well-suited to cancer genomics research:

• Non-invasive collection: Saliva and buccal swab sampling removes barriers to participant recruitment, particularly for community-based studies and those involving patients who may find repeated venepuncture difficult or distressing.
• Room-temperature stability: GeneFix™ products stabilise DNA at room temperature for up to 60 months, eliminating cold chain requirements and making postal sample collection straightforward
• Guanidinium-free chemistry: All GeneFix™ stabilisation buffers are non-toxic and guanidinium-free, making them safe for participants to handle at home and compliant with standard postal regulations.
• High-yield, high-purity DNA: Isohelix extraction kits are optimised to work with GeneFix™ collectors, delivering DNA of sufficient purity and integrity for demanding applications including GWAS, whole-genome sequencing and microbiome analysis.
• Scalability: Isohelix products are available in formats suitable for studies ranging from small, single-site investigations to large-scale biobanking programmes enrolling thousands of participants.

To find out how Isohelix can support your cancer research programme, visit www.isohelix.com or contact our team to discuss your sample collection requirements.

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[i] Breast Cancer Risk Assessment in Younger Women (BCAN-RAY) study. Manchester University NHS Foundation Trust / Cancer Research UK (ACED). Ongoing.

[ii] https://doi.org/10.1186/ISRCTN87845055

[iii]Gopinath, D., Menon, R.K., Wie, C.C. et al. Differences in the bacteriome of swab, saliva, and tissue biopsies in oral cancer. Sci Rep 11, 1181 (2021). https://doi.org/10.1038/s41598-020-80859-0

[iv] Nolasco B, Ehsan S, Wang R et al.Evaluating Genomic Changes as Biomarkers of Chemoradiation Therapy Response in Locally Advanced Cervical Cancer International Journal of Radiation Oncology, Biology, Physics, 123e368

The ability to collect high-quality nucleic acid samples in the field is key to conservation, population genetics, epidemiology, forensics, and environmental genomics.

However, collecting samples outside the lab can involve working in extreme environments, with unpredictable temperature changes, high humidity, exposure to dust and dirt, and the presence of water.

Read on to find out how scientists are using Isohelix products to collect high-quality nucleic acid samples from a range of environments, such as jungles, deserts, marine environments, and even from space!

The Challenges of Collecting Biological Samples in Extreme Environments

In the lab, it is relatively easy to collect and store biological samples. However, outside the lab, the sample collection and extraction workflow must be carefully considered to produce good results.

Extreme environments expose your precious samples to:

Stabilising DNA at the point of collection

Maintaining a cold chain for sample collection, storage, and shipment is particularly challenging when working in the field. With no power available for cold chain shipping and storage, logistics delays may mean that samples are not dealt with for a long time. For teams sampling in deserts, polar regions, offshore locations, or remote rainforest sites, maintaining sample stability at ambient temperatures can be the difference between success and failure.

Read our blog, https://isohelix.com/resources/how-to/how-to-maintain-the-integrity-of-dna-in-your-samples-without-freezing/,to find out more about Isohelix DNA Stabilization solutions.

Robust Packaging to Protect Samples

In extreme environments, contamination risks increase. Wind-blown dust, humidity, salt spray, mud, unsterile surfaces, and improvised field setups all increase the likelihood of introducing exogenous DNA or inhibitors. In these conditions, secure packaging and easy-to-handle collection kits are critical factors in maintaining sample integrity.

Isohelix collection tubes comply with UN3373 for leak-proof sample transport, which specifies that collection tubes must withstand a defined physical pressure differential of 95kPa. Transport packs for saliva and swab samples include an absorbent pad to contain leaks, a separate document pocket, and are tested to withstand 95kPa.

Click here to find out more about Isohelix packaging solutions

Summary

Isohelix kits and stabilization solutions empower researchers to collect reliable, high-quality DNA samples even in the most challenging field conditions. By safeguarding sample integrity through robust packaging, ambient temperature stabilization, and user-friendly collection devices, Isohelix enables vital research across diverse environments, from rainforests and deserts to the ocean and beyond.

Check out the publications below to see some examples of how Isohelix’s DNA collection and stabilisation products have been used to collect and stabilize nucleic acid samples in a range of challening environments:

Forest

Meier, Amelia C., et al. “Fruit availability and human disturbance influence forest elephant group size.” Animal Behaviour 203 (2023): 171-182.

Rivers

Gillman, Victoria H., et al. “Genomic evidence of local adaptation in Scottish freshwater pearl mussels.” Conservation Genetics 27.1 (2026): 10.

Adcock, Mia C., et al. “Population genomics of the endangered freshwater mussel, Arcidens wheeleri (Unionoidea: Unionidae: Anodontini), in the Little River, Arkansas, USA.” Journal of Molluscan Studies 90.3 (2024): eyae029.

Coastal Areas

Lee, Ji-Eun, et al. “Identification of Simultaneous Occurrence of Amphibian Chytrid Fungi and Ranavirus in South Korea.” Animals 15.14 (2025): 2132.

Cold Climates

Perrault, Charlotte, et al. “Dressed for the Weather: Tawny Owl Feather Adaptations Across a Climatic Gradient.” Ecology and Evolution 15.6 (2025): e71441.

Natural Habitats

Sinovas, Pablo, et al. “Giants in the landscape: status, genetic diversity, habitat suitability and conservation implications for a fragmented Asian elephant (Elephas maximus) population in Cambodia.” PeerJ 13 (2025) e18932.

Dicks, Kara L., et al. “Genetic diversity in global populations of the critically endangered addax (Addax nasomaculatus) and its implications for conservation.” Evolutionary Applications 16.1 (2023): 111-125.

Koutsokali, Maria, Christina Dianni, and Michael Valahas. “Buccal swabs as an effective alternative to traditional tissue sampling methods for DNA analyses in Chamaeleonidae.” Wildlife Biology 2023.2 (2023): e01052.

Helmstetter, Nolan A., et al. “Predator‐specific mortality of sage‐grouse nests based on predator DNA on eggshells.” Ecology and Evolution 14.10 (2024): e70213.

Space

Overbey, Eliah G., et al. “Collection of biospecimens from the inspiration4 mission establishes the standards for the space omics and medical atlas (SOMA).” Nature Communications 15.1 (2024): 4964.

Tierney, Braden T., et al. “Longitudinal multi-omics analysis of host microbiome architecture and immune responses during short-term spaceflight.” Nature Microbiology (2024): 1-15.

Your genomics results are only as good as the sample you start with, regardless of which sequencing platform or analytics packages you use.

Across population genetics, clinical research, microbiome studies, and diagnostic workflows, swabs remain one of the most widely used tools for DNA collection. Yet despite their apparent simplicity, not all swabs perform the same. In fact, your choice of swab can have a significant impact on sample integrity, nucleic acid yield, and therefore the overall success of your study.

At Isohelix, we’ve spent decades optimising swab and saliva-based sampling. Here’s what we’ve learned about why your choice of swab matters, and how Isohelix’s unique swab designs ensure you get the best from your samples.

Isohelix swabs deliver higher yields, better DNA integrity, simpler handling, and more consistent results, helping you protect your data quality from the very first step.

Read on to find out why world-class research groups use Isohelix collection kits for their studies:

Most Swabs Leave Material Behind

One of the most significant advantages of buccal swab DNA collection is its completely non‑invasive nMany standard swabs were designed for microbiological or diagnostic applications, but not specifically for collecting DNA. The fibre structure in the heads of these swabs can trap cells, but not efficiently release the sample into lysis buffer for nucleic acid extraction. This limites the amount of DNA that can be recovered.

Isohelix swabs use a unique swab matrix with a quick release surface specifically engineered to maximise sample capture and release.

Users consistently report:

• Higher DNA yields
• Higher purity
• Less variability between donors

This translates to fewer failed samples and better results.

The unique, Isohelix high-yielding swab matrix, ensures greater DNA yields.

Maintaining DNA Sample Integrity

As long-read sequencing, high-molecular-weight workflows, and advanced epigenetic assays become mainstream, the quality of DNA samples becomes increasingly critical.

To reduce the risk of sample deterioration and remove the cost of cold chain shipping and storage, Isohelix has developed a number of nucleic acid stabilization products, including collection tubes prefilled with BuccalFix reagent, Dri Capsules that can be added to tubes containing swabs, and Rapi-Dri collection kits that include a quick drying pouch that stabilizes DNA on a swab when it is placed inside.

Isohelix swab systems with proprietary stabilisation chemistries ensure:

• Long-term ambient sample stability
• Protection against nuclease activity
• Preservation of microbial composition (where required)
• No toxic chemicals, making shipping easier and safer

Whether you’re running a large epidemiological study or collecting samples in remote locations, stabilised swabs eliminate common failure points.

Simple Handling of DNA Samples

Isohelix products are designed by scientists, for scientists. We understand the challenges researchers face and have designed our products to be as straightforward to use as possible.

To ensure simple handling and efficient workflows, Isohelix collection and processing solutions include:

SwabCatcher Tubes Simplify Sample Handling

Another innovative product designed for ease of use is the Swabcatcher^TM tube, which features a unique cap that automatically removes the swab from the tube after lysis.

DNA Sampling of Small Animals and Invertebrates

Simple workflows from Collection to Extraction

In genomics and diagnostics, the pressure to deliver reliable, reproducible data has never been higher. The choice of swab might seem a small one, but the consequences of poor sample collection ripple through every stage of the workflow.

Isohelix swabs offer significant advantages over other swab designs in terms of cell collection efficiency, thanks to the unique swab matrix, which, combined with a quick-release surface, maximises yields of nucleic acids.

Isohelix is fully certified to ISO 9001:2015 and ISO 13485:2016, and holds membership of key medical device and regulatory bodies. Isohelix swabs are certified DNA-free and RNase-free, and are free of PCR inhibitors or enzymes that may contaminate your sample and prevent downstream analysis.

Find out more at isohelix.com, or contact us to discuss the best collection devices for your application.

Although Isohelix buccal swabs have been primarily designed for buccal applications, they have been used extensively for other applications, including skin, hard-surface sampling, teeth and gums, tongue, and stool/faecal samples.

If you have any queries about other tissues or sampling areas, please refer to Isohelix for further information.

DNA sample stability underpins the reliability of all downstream analyses, from multi-year population studies to high-resolution sequencing workflows. As analysis techniques advance, the requirements for high-quality DNA increase.

This article discusses how to ensure the stability of your DNA samples, covering the following points:

• What threatens DNA stability?
• Do DNA samples need to be frozen for long term storage?
• Isohelix stabilization solutions for saliva & buccal swab samples
• Stabilizing DNA in saliva samples
• Stabilizing DNA in buccal samples

What Threatens DNA Stability?

The DNA integrity of a sample can be reduced during shipping and storage via several mechanisms :

• Endogenous nucleases and chemical components within saliva or buccal cells rapidly digest unprotected DNA.
• Freeze–thaw cycles mechanically shear DNA
• Microbial growth during shipping not only increases the proportion of microbial DNA in the sample, but also introduces reactive enzymes and metabolites that may further damage DNA.

These risks are amplified in large-scale studies involving at-home collection, where samples may spend several days in transit and experience wide fluctuations in ambient temperature. Ensuring stability from the moment of collection to laboratory processing is essential.

Do DNA Samples Need to Be Frozen for Long Term Storage?

Isohelix Stabilization Solutions for Saliva & Buccal Swab Samples

At Isohelix, our mission is to help researchers get the highest-quality DNA from every sample. Isohelix stabilization reagents maintain DNA integrity for several years without the need for refrigeration or freezing. This not only reduces costs but also safeguards sample quality throughout shipping and long-term storage.

The stabilization chemistries are designed to protect nucleic acids immediately upon collection, enabling reliable downstream performance for sensitive applications such as microarray analysis, RT-PCR, and long-read sequencing.

Different workflows call for different formats, so we offer a suite of optimized solutions:
Stabilizing DNA in Buccal Swab Samples: Isohelix BuccalFix™ DNA Stabilisation kits are specifically engineered for long-term room-temperature storage of buccal swab samples. BuccalFix not only preserves DNA integrity but also enables high-yield, high-purity extraction.
Stabilizing DNA in Saliva Samples: For saliva-based workflows, Isohelix offers several tailored systems: • GeneFix™ Saliva Collection Kits – Prefilled tubes with DNA stabilization buffer – Available in 1 ml, 2 ml, and 3 ml saliva volumes – Maintain DNA stability at room temperature for extended storage or biobanking • SaliFix™ DNA/RNA Swab Collection Kits For studies preferring saliva collection using swabs, SaliFix is the recommended choice. SwabCatcher tubes prefilled with SaliFix buffer ensure rapid stabilization of nucleic acids in low-volume saliva swab samples.

Summary

DNA preservation must begin at the point of collection. Inadequate swab design, poor-quality saliva tubes, or suboptimal chemistries can allow nuclease activity, microbial proliferation, or temperature fluctuations to compromise your samples before they ever reach the bench.

Sometimes, for example when biobanking, samples may need to be stored for several years, without deterioration.

Cold chain shipping and storage, and sample freezing is no longer the best option. Choosing the right collection device and stabilization chemistry is one of the most important steps you can take to protect your samples, whether you plan to analyse them tomorrow, or ten years from now.

Isohelix offer a range of stabilization solutions to fit different study requirements. If you’d like information on the full range of Isohelix stabilization solutions, or help selecting the best stabilization format for your study, contact us on info@isohelix.com.

It’s been a busy year at Isohelix!

Looking back on 2025, one thing is clear – the demand for high-quality, reliable DNA sample collection has never been greater.

From population genomics and molecular diagnostics to long-read sequencing and biobanking, researchers are asking more of their samples and expecting more from the tools used to collect and extract nucleic acids.

At Isohelix, our focus is simple: to ensure you get the best results from your genomic samples.

Below is a summary of some of our key activities from 2025:

Scientific Meetings

In 2025, we kicked off the year at the Festival of Genomics and Biodata in London. This great meeting attracts >8000 participants, and we were proud to be one of the 120 life science companies with a booth at the event.

In May, we went to Milan for the European Society of Human Genetics Meeting. Then in October, we were off to Boston for the 75th Annual Meeting of the American Society of Human Genetics.

New Team Members

In November, we were delighted to welcome David Wilson to IsoHelix as Director, Business Development. David brings deep experience across the global IVD and diagnostics landscapes.

He is working closely with our commercial teams to drive our successful global growth in the clinical, diagnostics, and genomic markets.

SaliFix Swab Collectors

Over the past year, we’ve continued to see strong uptake of our SaliFix™ Swab Collectors, which include the new automation-friendly SwabCatcher™ tubes for improved sample handling and long-term DNA/RNA preservation.

Looking Ahead

As genomics moves faster and reaches further, sample quality remains critical.

In the year ahead, our focus remains on:

• Supporting advanced genomics and diagnostics workflows
• Helping customers reduce sample failure rates
• Enabling robust DNA collection in real-world conditions
• Providing innovative collection, stabilisation, and purification products allowing scientists to use non-invasive saliva or buccal swab samples instead of blood
• Removing the need for cold chain transport and storage of samples

Technical Resources and Blogs

It was a busy year for our writers – our most-read blogs from 2025 were:

• Five Common Mistakes to Avoid When Collecting DNA Samples
• How to Simplify Saliva and Buccal Swab Sample Collection and Processing
• Genomic Analysis with DNA from Saliva instead of blood

Find these and other educational tools and resources at https://isohelix.com/resources/

Thank You

Finally, we’d like to thank our customers, collaborators, and partners for trusting Isohelix as their partner for sample collection and purification. Your feedback continues to shape everything we do.

Here’s to another year of better samples, better data, and better science!

Follow Isohelix for insights on DNA collection, stability, and genomics best practice.

Get in touch if you’re planning a new study or scaling an existing one.

The quality of DNA extracted from donor samples affects the quality of data produced from genomic analyses, and as analysis techniques become more sophisticated, DNA quality becomes even more important. 

DNA samples are vulnerable to degradation during collection and transport. For many years, chaotropic guanidinium-based reagents such as guanidinium thiocyanate (GITC) and guanidinium hydrochloride (GHCl) have been used as constituents of nucleic acid sample collection buffers and extraction kits because they stabilize the nucleic acids in samples. For example, when extracting RNA, a mix of guanidinium thiocyanate, phenol and chloroform is often used, and is more efficient than phenol-only procedures. Guanidinium-based reagents disrupt cells and inactivate nucleases and are also commonly used to inactivate infectious viruses prior to nucleic acid testing. 

However, reagents containing guanidinium pose several operational and safety challenges. Guanidinium-free stabilization systems, such as the Isohelix nucleic acid sampling and purification portfolio, offer a compelling alternative that protects samples without compromising on safety, scalability, or downstream performance.

Nucleic acid sample collection and stabilization

The hazards of guanidinium-based reagents

GITC and GHCl are toxic and corrosive[i]. Working with kits containing guanidinium can require the use of personal protective equipment (PPE), hazardous waste processing, and can create shipping challenges. The hazardous nature of GTC and GHCl buffers limits their use in self-collection kits because of the potential for misuse by members of the public.

Does guanidinium interfere with downstream assays?

Isohelix products are safe and effective, without hazardous components

As sample collection has expanded beyond specialist labs and into decentralized, high-throughput, and at-home workflows, guanidinium-based chemistries have become increasingly problematic.

Over the past two decades, saliva-based DNA collection has become routine for population-scale genetic studies, clinical research, and emerging diagnostic applications. Using Isohelix products, saliva collection is safe and non-invasive, and saliva collection kits can be mailed to donors for self-collection at home.

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Requirement	Why it matters
Room-temperature stability	Supports global logistics and eliminates cold chain dependency
Non-toxic formulation	Enables use in community, home, and non-clinical settings
Inactivates Pathogens No hazardous gas risk	Safe shipping and handling of samples Safer workflows
Protection of both DNA & RNA	Flexibility for multi-omic applications
Compatibility with PCR, NGS, long-read sequencing	No inhibitors, no yield loss, no extra cleanup
Lower regulatory profile	Easier approvals, fewer transport restrictions

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[i] https://www.fishersci.com/store/msds?partNumber=BP221250&productDescription=GUANIDINE+THIOCYANATE+250GR&vendorId=VN00033897&countryCode=US&language=en

[ii] U.S. Food and Drug Administration. Transport Media Safety Risk—Use Compatible Transport Media with SARS-CoV-2 Tests that Use Bleach—Letter to Clinical Laboratory Staff and Health Care Providers (2020).

[iii] Public Health England. SARS-CoV-2 Inactivation Testing, Isohelix GeneFixTM Buffer. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/937435/HCM-CoV2-036 v3_GeneFix_Buffer_TCF__1_.pdf

[iv] Public Health England. SARS-CoV-2 Inactivation Testing, Isohelix BuccalFix Buffer. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/937438/HCM-CoV2-035- v3_BuccalFiX_Buffer_TCF__2_.pdf

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The success of any genetic analysis study depends on high-quality DNA sample collection. Isohelix products are made by scientists, for scientists. In this blog, we share tips on how to avoid common mistakes when collecting DNA samples, based on our many years of experience.

Common mistakes:

• Sample contamination
• Incorrect Sample Storage
• Insufficient sample material
• Sample mix ups
• Sample tubes leaking during storage or transport

1. Sample contamination

Using non-sterile collection kits, poor sample handling, or eating and drinking before collecting saliva or buccal swabs, can lead to samples contaminated with foreign DNA or compounds that inhibit downstream applications.

Our top tips to avoid sample contamination are:

2. Incorrect Sample Storage

In our blog https://isohelix.com/how-to-maintain-the-integrity-of-dna-in-your-samples-without-freezing/, we discuss the range of Isohelix stabilization products so that you can choose the one best suited to your needs.

3. Insufficient sample material

Sometimes it can be challenging to collect sufficient sample material. When swabbing a surface or collecting buccal samples, use firm pressure to ensure good contact with the area to be sampled.

4. Sample mix-ups

Easy and accurate sample tracking is a key component of sample collection and isolation. Incorrect labelling can lead to sample mix-ups. For large numbers of samples, automated systems reduce handling errors, save hands-on time, and increase processing throughput. 

5. Sample tubes leaking during storage or transport

Collection tubes and sample packaging must be sufficiently robust to protect your valuable samples. With the correct packaging, stabilized samples can be sent to the laboratory for processing using regular mail, a safe, straightforward, and cost-effective method of sample transport.

Isohelix collection tubes comply with UN3373 on leak-proof sample transport, which specifies that collection tubes must withstand defined physical pressures of 95kPa.