Background:
DNA extraction from clinical specimens is one of the most important steps of molecular genetic tests, however it is difficult and not reproducible to extract DNA from minute amount of whole blood specimen. For the better quality control in
molecular
genetic tests, we compared various DNA extraction methods and proposed a reproducible and the most suitable one for minute blood specimen.
Methods:
DNA was extracted from 100 or 200μL of two EDTA-whole blood samples with normal WBC count and two with abnormally low WBC counts, respectively, using six methods: "Direct boiling/Proteinase K", "DTAB/CTAB" AND "Miniscale salting-out" methods,
and
two different commercial kits. We evaluated the degradation of DNA, the reproduciblity of repeated DNA extractions, and the quality and quantity of PCR products(214 bp and 704 bp of β-globin gene) using the extracted DNA.
Results:
It was possible to obtain the undegraded DNA which produce 214 bp and 704 bp PCR products by all of the above methods except "Boiling method." Boiling method yielded degraded DNA which could not wake 704 bp PCR products. DNA isolation was very
rapid
in "DTAB/CTAB method" and the comercial kist. The DTAB/CTAB method and the one commercial kit showed very low CV value(<1.0%)
Conclusions:
We recommend the DTAB/CTAB method as a suitable DNA preparation procedure from minute amount of whole blood. Using this method we could obtain the high quality and quantity of DNA with low cost and good reproducibility in 30 minutes.
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