Unlike all buffer components, EDTA is tetravalent and has four pK values. Hence it conducts more electric current producing more heat. Since generations they are there in text books and so no explanation is given to justify the need of each component in known amount per liter. Are we not stagnant in our approach to the science as such ?
EDTA chelates multivalent ions such as Mg++ and Mn++ and Fe+++. Magnesium is needed for enzyme activity so makes dnases and rnases and other nucleases inactive so is good for preserving the integrity of dna and rna in all buffer and storage media
What about hemoglobin electrophoesis, in which primary screening is recommanded by cellulose acetate membrane electrophoresis at alkaline pH. The sole buffer recommanded in all books is Tris:EDTA:Borate ?
Hi there,
EDTA is used as anticoagulant in blood samples (inhibiting the proteolytic process of coagulation) and I also guess EDTA is in charge to release and chelate iron from hemoglobin in order to have a uniform population of hemoglobins.
haemoglobins are only separated after cell lysis which may release proteases . If these proteases also need magnesium then removing Mg will lead to cleaner separation of intact Hb without too much degraded HB perhaps
Thanks Paul for your prompt response. Hemoglobin electrophoresis is done with Tris-Glycine, Tris-Tricine (equimolar concentration of both gives pH 8.25). You can lyse the washed red cells with water, Saponin, Triton X-100 or simply freeze thawing. I do not think the protease problem has any effect on hemoglobin molecule.
Researchers suffer from "bitemporal hemianopia (tunnel vision), Whatever appears in texts or kit insert is taken at face value as "biblical truth" ! Tangential thinking is not needed in publishing paper. After all, life is best when the path of least resistance is chosen. Be happy.
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