In this process 1 mol of O2 consumed
is equivalent, stoichiometrically, to 2 mol of INT reduced and 2 mol of
formazan produced. The formazan is measured spectrophotometrically
at 490 nm. This is a measurement of the ability of mitochondria and microsomes
to transfer, physiologically, electrons from substrates (NADH,
NADPH and succinate) to a final electron acceptor. It is the respiratory capacity
(or potential respiration) and in the parlance of enzymology, the
maximum velocity of the ETS, its Vmax.