anybody an expert on Fiske & Subarrow assay?

Jon Nakamoto jnakamot at
Sun Oct 15 02:19:54 EST 1995

I have a friend who is trying to calibrate his Westerns (normalize for
differing amts of sarcolemma in fetal vs. adult cardiac membranes) by
Na+-K+ ATPase activity in the membrane extracts. He's basically trying to
measure ouabain-sensitive Pi release using the Fiske & Subbarow assay for
inorganic phosphate, but hasn't been having much luck, even using RBC
membrane preps on which to troubleshoot and get the assay working. 

Anybody out there who is both familiar with this or an equivalent
phosphate assay (or, even better, who has experience measuring Na+-K+
ATPase activity in cardiac membranes) and is willing to field a few
questions from my friend? Or perhaps supply a detailed protocol of what
works for you? (Yes, he has the pertinent Meth Enzymol and even the
original articles). 


Jon Nakamoto, M.D.
UCLA Medical Center
jnakamot at 
jnakamot at
fax 310-206-5843

Jon Nakamoto
jnakamot at

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