Hello, 

Does anyone know anything about the mechanism of myosin ATPase stains? What
is it about pHs of 4.3, 4.6, 9.4 that affects subsequent enzyme activity
rates? 

I ask because some procedures incubate at room temp. and some at 37C, BUT
almost ALL adjust pH to 9.4 at room temp. A pH 9.4 glycine buffer at room
temp will actually be 8.9-9.0 at 37C.  

Is this possibly the underlying reason some stains specify pH of 9.6 or 10.3
for the incubation solution? 

Is this at the root of the inconsistentcies people experience with the
ATPase stain? 

Subtle temperature and buffer dependent pH effects might put the incubating
solution near a fence between working conditions and failing condidtions.
Small variances in solution conditions could then dramatically affect the
staining.

What is the "real" pH that the myosin ATPase enzyme prefers? Where would I
look?

Thanks for all your thought,
Sincerely,
-brice

P.S. we too experience unexplainable problems - we use a modification of
Joan Round's procedure.