A method for the spectrophotometric assay of anaerobic enzymes.

A convenient and inexpensive system for conducting large numbers of spectrophotometric assays at wavelengths between 300 and 750 nm under strictly anaerobic conditions has been developed. Round test tubes or round cuvettes stoppered with either thick black rubber stoppers or thinner red rubber stoppers are used to replace rectangular cuvettes. The round tubes are held in place in the spectrophotometer by a simple metal holder. Additions to the tubes are made by syringe using a specially constructed needle guide to prevent needle bending.