PDQeX Standard kits contain lower cost cartridges and reagents that work with the simpler sample types (dispersed cells such as saliva and buccal swabs, vaginal swabs and saliva deposits on cigarette butts). Two versions are provided: PDQeX prepGEM Standard works for a wide range of samples used by the Life Sciences and PDQeX forensicGEM Standard which uses the same formulations but undergoes the more rigorous preparation and testing (ISO18385) the forensic community needs.

Buccal Swabs

PDQeX Standard kits are especially effective for extracting DNA from buccal swabs, liquid saliva and saliva stains.

  • The simplicity of the method maximizes yields of DNA from trace samples.
  • The kit’s optimized methods and formulations provide DNA in 10 minutes.
  • All buffers and reagents are PCR compatible and work with commonly used profiling kits.
  • The methods are closed-tube and hands-off – protecting the integrity of the sample and the safety of staff.

Method:

  1. Rinse mouth with water for 30 sec before taking a buccal swab sample.
  2. Put 600 µl of sterile, DNA-free water in a 2ml Eppendorf tube.
  3. Rub 2x cotton swabs (1 per cheek) along the inside of the cheek and gums for 30 sec per swab.
  4. Run each swab in the 600 µl water with a swirling motion along the sides of the tube. (Remove as much liquid from the swab as possible by pressing it along the rim of the tube before disposing it).
  5. Make a reaction mix as follows:
Blue buffer10 µl
prepGEM/forensicGEM2 µl
Buccal solution5-20 µl
DNA-free waterMake up to 100 µl
  1. Add 100 µl of reaction mix to the PDQeX Standard cartridge.
  2. Run the default program:
75˚C5 min
110˚C2 min

Typical Results:

 

 

 

 

 

 

 

 

qPCR plots using reagents from two different vendors. The two plots on each graph are 5 µl of undiluted extract and 5 µl of a 1:5 dilution in a 20 µl qPCR. Efficiencies are approaching 1 and no obvious inhibition is seen.

Saliva on Storage Cards

Method:

  1. Rinse mouth with water for 30 sec before taking a buccal swab sample.
  2. Rub 2x cotton swabs (1 per cheek) along the inside of the cheek and gums for 30 sec per swab.
  3. Run each swab on a storage card (Whatman 903/FTA Classic/FTA Elute) and allow to dry.
  4. Pre-wash a 3 mm punch of the storage card by submerging it in 100 µl DNA-free water. Leave it to ‘wash’ at room temperature for 15 mins.
  5. Make a reaction mix as follows:
Blue buffer10 µl
prepGEM/forensicGEM2 µl
DNA-free waterMake up to 100 µl
  1. Remove the 3 mm punch from the wash tube and add it to the PDQeX cartridge.
  2. Add 100 µl of reaction mix to the PDQeX cartridge, ensuring the storage card punch is submerged in the reaction mix.
  3. Run the default buccal program:
75˚C5 min
110˚C2 min

Results:

 

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