Immobilized-enzyme membrane sandwich reactor used in automated micro-scale assay of plasma uric acid.

We describe the automated microassay of plasma uric acid by use of an immobilized uricase-membrane sandwich reactor. Hydrogen peroxide, formed when uric acid is oxidized, oxidatively couples two molecules of p-hydroxyphenylacetic acid in the presence of peroxidase to produce a highly fluorescent compound. The specificity of the uricase reaction is coupled with a significantly lower cost of analysis.