A quantitative fluorescence lipase assay based on the interaction of r
hodamine B with fatty acids released during the enzymatic hydrolysis o
f triglycerides is described. The assay is linear over the range of 0.
5-2 mM oleic acid and 0.05-1 mu g pure lipase. The method allows flexi
bility in the choice of substrate. A large number of samples can be as
sayed simultaneously, making it practical for assaying lipase activity
in column fractions during purification. The substrate profiles of Ge
otrichum candidum lipase obtained by both a titrimetric assay and the
RTA assay indicated the highest activity against triolein. The method
is rapid and can be further automated. (C) 1994 Academic Press, Inc.