Abstract: A process for the production of a homochiral 2-hydroxy carboxylic acid or salt thereof corresponding to general formula (I), wherein R represents one of formulae (II), (III), (IV), (V), wherein R' represents straight- or branched-chain alkyl or phenyl optionally para-substituted with methyl, methoxy, nitro or amino; and R" represents hydrogen, halogen or phenyl optionally para-substituted with methyl, methoxy, nitro or amino; and M represents hydrogen or a salt-forming moiety; characterized in that it comprises reducing a corresponding 2-keto carboxylic acid or salt thereof using a (R)- or (S)-2-oxo carboxylic acid dehydrogenase, inter alia, is disclosed.

Abstract: Inter alia, a process for the selective removal of salivary .alpha.-amylase from a sample comprising salivary .alpha.-amylase and pancreatic .alpha.-amylase characterized in that there is used a monoclonal antibody against salivary .alpha.-amylase, which is immobilized or is coupled to a physically separable or seperate support and which exhibits a binding affinity towards salivary .alpha.-amylase of at elast 1.times.10.sup.7 l/m and a cross-reactivity with pancreatic .alpha.-amylase of less than 1% is disclosed. The remaining pancreatic .alpha.-amylase may be assayed.