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DNA extraction from blood - Gelatinous material in aqeous phase (Mar/18/2002 )

I am trying to extract DNA from mammalian blood
but while doing the phenol extraction a lot of Gelatinous material in aqeous phase creating problem in its separation.
Can somebody tell me how to minimise it?
What is its chemical composition? whether it is protein/lipid or carbohydrates?

-dillip karna-


maybe this gelatinous component is composed of proteins so you can try proteinase K 1mg/ml final, 55/60c from 2 hours to ON. It will be better for the phenol/chloro.



Dear Researcher,

As you probably know, the proteins are readily denatures in low pH, e.g. when come to contact with phenol (phenic acid).
If you want to extract the genomic DNA from the hematopoietic cells, you may easily decrease the protein content of your desired sample, for example by washing the blood specimen in an isitonic buffer or saline in order to discard the plasma and retain the cells. Then add the phenol solution ! No need to the cumbersome and expensive use of Proteinase K.

M. Mahdi Mohammadi, LMD, PhD
Immunology Dept.
Tehran University of Medical Sciences
Tehran, I.R.Iran