My son is writing up a school project in which he carried out
experiments to calculate the Km of alkaline phosphatase acting on p-
nitrophenylphosphate in both ELISA and when the enzyme is free in
solution.The experiments were carried out at 25C and at a pH of
9.8.The result was Km= 0.246 for the immobilised enzyme and 0.505
for the free solution. I would be grateful for any comments on these
results. It means that there was greater affinity of the enzyme for the
substrate when it was immobilised, which is not what we expected.
Isla Browning
Diagnostics and Molecular Biology Section
SASA
Edinburgh
Tel
