Table of Contents
In theory, swab-based sample collection should be an ideal method for collecting and transporting samples for several reasons including:
- Easy and simple to use: Almost everyone knows how to use a swab
- Can access difficult to reach places. This is especially helpful for forensics and environmental sample collection.
- Makes sampling accessible to all population age groups and animals, positioning it to be a true universal sample collection tool
Unfortunately, swabbing in its current format has proven to be only suitable for simple genomics applications with documented failure rates as high as 60%. Some of the issues that current swab based collection suffers from include:
- One swab per sample: Results in low recovery rendering it mostly unacceptable for downstream applications, especially for genomics based assays. In many cases, the donor is required to re-submit the sample, increasing cost and compromising research.
- High sense of urgency to send the collected swabs back to the lab, increasing transport costs.
- Handling swabs in the lab is a labor-intensive process: A manual pre-treatment step is always required before proceeding to sample recovery (10-30 mins/sample).
- High bacterial DNA contamination, especially for cheek & vaginal swabs resulting in high failure rates in downstream applications. Opportunity loss is unmeasurable, as some samples can be difficult or impossible to be collected or retrieved a second time.
- Swabs need to be processed within 72 hours to recover any usable DNA. Otherwise, samples must be stored long-term at -80°C.
The iSWAB universal sample collection technology is designed to transform traditional swab-based methods from providing low quality sample that might be limited to simple genomics approaches to a high quality and more efficient sample collection tool that can address both simple and complex genomics, proteomics, and drugs screening assays while stabilizing samples from point of collection to processing. By removing the need to return swabs with the iSWAB tube, both manual and automated sample processing becomes much more streamlined and cost effective in the lab. Basically, iSWAB simplifies sampling from collection to processing with room temperature transport and long-term storage. iSWAB samples have been shown to be room temperature stable for 2.5 years (with ongoing real time testing) and for 5 years under accelerated stability testing conditions.
Three steps: Collect – Release – Transport (2-4 min process)
- Collect: Using a commonly available swab, collect the biological material of interest
- Release: By inserting the swab through the iSWAB tube, the biological content collected on the swab head is released with the help of the scraping insert positioned inside the iSWAB tube. The collected material is then stabilized for long term room temperature storage in the proprietary iSWAB buffer. Depending on assay requirements and the biological material collected, samples from additional swabs can be consolidated into a single iSWAB tube which allows further concentration of the sample.
Transport: The iSWAB sample can be transported at room temperature using standard postal mailing services. Every iSWAB sample has a unique barcode to maintain chain of custody. The iSWAB tube temperature range for long term storage is -80°C to 65°C.
Each iSWAB tube format is optimized for sample collection and stabilization per application (check product listing for more details):
- Human gDNA: iSWAB-DNA, iSWAB-ID, iSWAB-Discovery
- Animal gDNA: iSWAB-Animal, iSWAB-Discovery
- Forensics: iSWAB-ID
- Microbiome: iSWAB-Microbiome
- Human RNA: iSWAB-RNA, iSWAB-Cells
- Animal RNA: iSWAB-RNA, iSWAB-Cells
- Proteomics: iSWAB-Protein, iSWAB-Cells
- Drugs; Primary and Secondary metabolites: iSWAB-Protein, iSWAB-Cells
- Blood drops/FTA replacement: iSWAB-Blood
- Human gDNA/RNA/Protein from the same sample: iSWAB-Cells
- Genotype vs. Phenotype: iSWAB-Cells
iSWAB sample collection kits are supplied with 1-4 sterile swabs, depending on the DNA, RNA, or Protein yield requirements. The iSWAB kits contain flocked nylon swabs, cytobrushes, or cotton swabs depending on the application. The following swab types are compatible with iSWAB:
- Cotton or Q-tips
- Flocked, nylon swabs
- Rayon swabs
- Dacron swabs
Foam or sponge based swabs are NOT compatible with iSWAB as they can absorb the stabilizing buffer during the release process and may not fit through the scraping insert. More importantly, when used for oral sampling foam swabs collect mainly saliva which has high bacterial DNA contamination therefore affecting the outcome of human or animal based genomics assays. iSWAB is specifically designed to collect buccal cells with minimal bacterial DNA contamination.
iSWAB is optimized for room temperature transport and long-term storage to reduce shipping costs and the need for cold temperature infrastructure. However, it has been tested for stability at a wide temperature range (-80°C to 65°C).
Basically any workflow that utilizes swab-based collection and/or any application that requires a high quality sample:
DNA sequencing; Sanger and Next generation sequencing: iSWAB-DNA
Genotyping: PCR and microarray based (iSWAB-Discovery)
Gene Expression: QPCR and RNA based sequencing (iSWAB-RNA or iSWAB-Cells)
Proteomics: Mass spec, ELISA, Western blotting, SDS-PAGE (iSWAB-Protein or iSWAB-Cells)
Population genomics/ Cancer research HLA Typing: iSWAB-DNA
HLA Sequencing based typing/ Pharmacogenomics/ Animal speciation & breeding: iSWAB-Discovery
Transcriptomics: iSWAB-RNA or iSWAB-Cells
Microbiome (Fecal, skin, vaginal, soil etc.): iSWAB-Microbiome
Genotype vs. Phenotype: iSWAB-Cells
Neonatal genetics screening: iSWAB-Blood
Drug marker screening: iSWAB-Protein
Human or animal gDNA extraction: Any commercially available kit for extracting human gDNA from whole blood (either manually or automation-enabled) can be used without any further modifications (check the list of validated chemistries), as well as phenol chloroform or ethanol precipitation.
Human and animal RNA extraction:
SDS-PAGE & Western Blotting: http://mawidna.com/wp-content/uploads/2016/04/Detection-of-Frataxin-using-iSWAB-Protein-UAB.pdf
Antibody based analysis: http://mawidna.com/wp-content/uploads/2013/06/iSWAB-Protein-Datasheet-v1.01.pdf
Human and animal gDNA, RNA and protein: Primarily obtained from buccal cells for oral based sampling. The buccal cell genome is known to be a surrogate for several major organs such as the brain, liver, kidneys etc.
Unlike saliva based collection, the human or animal gDNA from iSWAB is recovered as long, double stranded fragments with limited bacterial and non-host DNA contamination (e.g. food particles or residue), providing better DNA sequencing coverage and lowering the cost of the whole NGS based assay.
Microbial DNA or RNA from any source or surface: The stabilizing buffer in the iSWAB-Microbiome allows for obtaining microbial DNA or RNA with limited host contamination.
For human and animal sample collection: First thing the morning before brushing teeth, drinking, or eating.
Microbiome samples: Release swab content post collection into the iSWAB tube immediately after collection.
Collaborators from Boston University have shown that the iSWAB-ID can maximize the recovery of gDNA from old swabs, which was then successfully analyzed using human STR profiling kits. The study shows that the recovery of usable human gDNA was 70% higher when using iSWAB-ID as opposed to standard DNA recovery methods (please inquire for more details).
Please check the data sheet for individual sample collection kits.
The proprietary iSWAB buffer is a unique formulation that not only stabilizes the samples at the point of collection, but performs a gentle lysis which slowly releases DNA from the cells into the buffer over a period of several hours. This feature enables the mixture to be used in a direct-to-PCR application, in which the extraction step is skipped entirely (check the resources section for further information) . The benefits of this application are:
- Time, cost, and labor savings by eliminating extraction reagents and processing time
- Rapid field-based analysis
For more complex downstream applications such as Next Generation Sequencing or microarrays, however, we still recommend performing a standard DNA extraction (please inquire for more details).