Chelex Extraction Protocol

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Description

This is a nice and easy method to extract DNA, it is particularly useful for small organisms because it gives a big yield and it is possible to remove the body for slidemounting/further morphological work after extracting the DNA. It is a "dirty" extraction because the proteins and other contaminants are not removed from the extract, it's only really good for PCR applications as a result. According to wikipedia the exact role of Chelex in DNA extraction is uncertain but it works well nonetheless!

What you need

Chelex resin available from BioRad

Protocol

  1. Prepare a truncated p1000 tip (cut the end off with scisors so the chelex balls will go in)

  2. Switch on heating block and set to 98oC, put Chelex on stirrer and switch on

  3. Add 200µl to 500µl of Chelex solution and sample to eppie tube

  4. Vortex tubes

  5. Spin down on high speed for 1 minute to make sure sample is below the surface of the Chelex solution

  6. Heat the tubes @ 98oC for 10 to 20 mins

  7. Spin them down briefly and cool on ice (or in the freezer) for 5 mins

  8. Centrifuge at high speed for 10 mins

  9. DNA is now ready to use, spin before each use and make sure to never get any chelex beads into a PCR or it will kill it :-(

Recipes

100 mL of 20% chelex in TE (10mM Tris HCl & 1mM EDTA pH8.0)

Clean H2O50ml
1M TRIS-Hcl ph81ml
0.5M EDTA200µl
Chelex resin20g
make up to 100ml with clean H2O