Chelex Extraction
Definition
A rapid extraction method that uses the chelating resin Chelex 100 to bind divalent metal ions and prevent nuclease activity. Cells are boiled directly in the Chelex suspension. The method is simple and inexpensive but yields single-stranded DNA and is not suitable for restriction fragment length polymorphism analysis.
- Reagent
- Chelex 100 resin
- Step
- Direct boiling of cells in Chelex suspension
- Cost/speed
- Simple, inexpensive, fast
- Limitation
- Single-stranded DNA, unsuitable for RFLP
Common questions
Why can Chelex-extracted DNA not be used for RFLP?+
RFLP requires intact, high-molecular-weight double-stranded DNA for restriction enzyme digestion, but boiling during Chelex extraction denatures and fragments the DNA, so it works for PCR-based typing but not for RFLP.
What downstream typing method is Chelex extraction best suited to?+
It is well suited to PCR-based STR typing, where only short single-stranded template regions need to be amplified, which is why it remains popular for quick screening and reference samples despite its output quality limits.
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