How NH4Cl/KHCO3 lyses RBC? - molecular/cellular mechanism? (Oct/13/2006 )

My question is pretty much in the topic. I have a recipe for RBC lysis buffer which goes like this:

• 8.24g NH4Cl
• 1g KHCO3
• 40mL 0.5M EDTA pH 8.0
• water to 1000mL

My additional question is: what is the function of all that stuff there? I know NH4 ions is the most important participant in the lysis. But why HCO3 anions? Why EDTA?

I'd much appreciate explanation with links to some articles.
Big thanks,
AAV

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it should have sth to do with suppression of Na+-K+-ATPase activity, lysis works then in absence of Na+; NH4+ is only minorily permeant for cell membrane; carbonate works as buffering component; EDTA which complexes Mg2+ and Ca2+ add to lysis by destabilizing membrane; less effected are leukozytes, so this lysis buffer discriminates between red and white blood cells which is of relevance as enriched euthrocytes may still contaminated by leukocytes

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