The simplicity of prepGEM™ Storage Card Blood maximizes yields of DNA from trace samples.
DNA Extraction
Using
prepGEM™ Storage Card Blood
prepGEM™ Storage Card Blood is a kit specifically developed for extracting DNA from animal blood stored on FTA cards.
- The kit’s optimized methods and formulations provide DNA in just 30 minutes.
- There are no multiple centrifugation steps, washes, vacuums, or columns.
- All buffers and reagents are PCR compatible with common profiling kits.
- The methods are closed-tube and hands-off.
These features make prepGEM™ Storage Card Blood particularly valuable for high-throughput automation of high-volume crime samples. The procedure is easily adaptable for 96-well plates and automation, and the closed-tube nature of the method protects the integrity of the sample through the extraction procedure.
Workflow
Extraction Method
Sample Preparation
All manipulations should be performed in a clean room or a PCR hood. Use only certified DNA-free tubes and reagents and wash surfaces likely to come into contact with the samples in 0.05% hypochlorite bleach. Rinse thoroughly with DNA-free water.
1. Remove one or two 1.2 mm discs from the card-stored sample and place into a thin-walled PCR tube or a 96-well tray.
For the best results, punch in the center of the area where the sample was applied.
2. Wash the disk in 100 µl of DNA-free water by incubating at room temperature for 15 minutes. Aspirate the water from the disc and discard.
Extraction Method
1. Add:
- 5 µl of 10x buffer MAGENTA
- 44 µl of DNA-free water
- 1 µl prepGEM™
2. Incubate at 75°C for 15 minutes.
3. Incubate at 95°C for 5 minutes. A thermal cycler can be used for this step
4. Centrifuge for 5 minutes at 16,000 x g and transfer the supernatant to a fresh tube.
The DNA is in this solution - not the punch.
The sample is now ready for quantification and analysis. Typically, 2 - 5 µl should be used in PCR
Technical Tips
- The prepGEM™ Storage Card procedure can be automated using most liquid handling robots.
- prepGEM™ Storage Card is a preparative method for DNA extraction from most types of storage cards. Its purpose is to lyse cells and to strip the DNA of nucleoproteins. Extracted DNA can be used for SNiPs, STRs, quantitative, multiplex and routine PCR applications.
- Storage cards for cells and DNA contain preservatives that can seriously inhibit Taq DNA polymerase. The pre-soak step is to remove these inhibitors and is essential for reliable results.
- prepGEM™ extracted DNA is largely single-stranded because of the heat step. If double-stranded DNA is required, the 95° step can be omitted and standard downstream purification procedures can be used.
- For accurate yield assessment, a qPCR is recommended. The DNA produced by prepGEM™ is approximately 90% single-stranded. If standard fluorescent chelating dyes are to be used for quantification, this factor should be taken into consideration.
- As with any preparative method for nucleic acid extraction, for best results prepare and manage samples at 4ºC, or on ice, before and after extraction.
- When storing the sample after extraction, aspirate the supernatant from the card punch.
- prepGEM™ is stable for 30 days at 4º C; for longer-term storage prepGEM™ should be stored at -20ºC.
- For long-term storage of the extracted DNA, add TE buffer to 1x and store at -20°C.