The Latest DNA Isolation Technology Available

Nucleic acid can provide information about many aspects of living organisms; including identity, composition and variation over time. As correlations are constantly being drawn between genetic information and functional characteristics, DNA is becoming an increasingly valuable tool in both research and everyday life. Whether the sample is recombined plasmid, a trace blood spot from a crime scene, or a buccal swab (saliva sample) used for our GenetiKid DNA ID Kit; nearly all DNA applications require sample archiving. Historically, successful storage and recovery of DNA required test tubes, hazardous buffers, ultra-low freezers and storage media. FTA® however, has successfully demonstrated that DNA can be stored at room temperature for many years and remain stable for analysis.

FTA technology for processing nucleic acids was invented by Professor Leigh Burgoyne of Flinders University, Australia. FTA features a chemically treated paper matrix for the safe collection, transport, storage, purification and analysis of DNA. Blood, saliva, bacteria, viruses, plant and soil samples can be conveniently processed for analysis. Hundreds of samples can be processed in a day using the FTA system as opposed to a handful using tradional DNA and RNA processing methods. This gave rise to the name FTA, Fast Technology for Analysis of nucleic acids.

Only small samples of FTA material (about 2 square millimetres) need be used for analysis. FTA is a generic technology with a wide range of application in research, diagnostics, environmental science, forensics and DNA data-bases. The USA postal seervice has approved the FTA system for transporting DNA (blood) samples through the mail. This is important for handling blood with dangerous mico-organisms such as HIV, Hepatitis C and Herpes virus.

Child Protection Aust. uses the FTA DNA isolation method which consist of a chemically-impregnated, cellulose matrix that can bring a sample from collection to analysis in only a few hours, or can archive a sample for decades. The FTA chemicals lyse cells upon contact with the paper, freeing the nucleic acid. The DNA becomes entrapped within the fibers of the matrix while the cell debris remains unbound for future removal. FTA protects the DNA from light, UV and free radical damage. The DNA is also protected from nucleases because FTA denatures protein on contact. This also inactivates any pathogens or microbes present in the sample, making potentially harmful blood samples safe for the handler. Since FTA lyses cells on contact, the sample is protected from microbial and fungal degradation during storage.

FTA cards can archive and purify DNA from blood, buccal cells, plant tissue, bacteria and many other biological sample types, all at room temperature. Field collection is simplified with FTA because no extraneous materials, equipment or buffers are needed; just an FTA card. Long-term archiving is made more convenient with a file cabinet, or a lab book, replacing rooms of -70°C freezers. Finally, purification is simplified with FTA because the immobilized nucleic acid is rinsed in two mild buffers rather than processed with expensive kits or home-brew methods that can be hazardous and time consuming. The quality of DNA obtained from sample collected, stored, and processed on FTA has been demonstrated by experimental data and real-world results alike. The use of FTA in genetic ID applications yields analytical results consistent with traditional methodologies. Storing bacterial clones on FTA allows researchers to transform or amplify from a sample pulled from a lab notebook rather than the freezer room.

This application note describes the latest results obtained from an on-going FTA stability study. These results report on the functionality of blood and buccal samples stored on FTA cards for 14 and 5 years, respectively. The long-term functionality of FTA is determined by the quality of the STR profiles generated from the aged samples as compared to the profiles generated from internal controls. STR (short tandem repeats) analysis was chosen to determine longevity because identification is the most common application for archived samples such as blood or buccal cells. Whether the sample is of a convicted felon for databasing purposes or from a thoroughbred horse for an insurance policy, DNA archived on FTA is often used for identification and must be suitable for STR analysis.

Testing Procedure
Outside Lab - Sections from both the blood and buccal samples were mailed to an outside lab that specializes in genetic identification testing.
Standard Punch Processing - Punches (1.2mm diameter for both blood and buccal samples) were manually taken from the sample-sections and were washed according to standard protocols.
Amplification - Processed punches from each sample were amplified using ABI AmpflSTR® Profiler™ and Cofiler™ Systems. The reaction volume was 10µL and the cycle number was reduced to 24 for all reactions.
Detection - A 10µL sample preparation (1µL amplified sample, 0.5µL GS ROX 500, 8.5µL de-ionized formamide) was detected using an ABI 3100 Genetic Analyzer. The default injection parameters were modified for the following: 3kV injection voltage and 5 second injection time for buccal samples, 15 seconds for blood samples.
Analysis - GeneScan® Analysis version 3.7.1 was used to analyze the raw data. Genotyper® version 3.7 was used to assign the allele calls.

Conclusion
FTA technology simplifies DNA analysis by facilitating sample collection, storage and purification using a single device; all at room temperature. The ability to preserve sample integrity during archiving makes FTA a valuable tool for genetic identification as analysis typically occurs after many years of storage. FTA can archive blood for 14 years at room temperature and the DNA remains suitable for STR analysis. Buccal samples are also extremely stable on FTA as evidence. Buccal samples have considerably less DNA than do equivalent blood samples. However, with the same size punch, the buccal sample produced a profile that has the same quality characteristics as the blood profile. Protection and purification are the two most important aspects of DNA analysis and FTA offers both in the most convenient platform available. The STR profiles obtained from the 14-year blood and 5-year buccal samples demonstrate that FTA both protects the DNA during storage and provides a rapid, effective purification method.

Available to You Today
This DNA Isolation Technology is now available to the public through our new Child Safety ID Complete Kits. You can rest assured there isn't a better DNA storage technique available to the public anywhere. Child Protection Aust. is a leader in ID Kit technology!