Pyocyanin Extraction and Quantitative Analysis in Swarming Pseudomonas aeruginosa

Abstract

This protocol describes the quantification of pyocyanin extracted from swarming colonies of Pseudomonas aeruginosa. Pyocyanin is a secondary metabolite and a major virulence factor, whose production is inducible and varies highly under different growth conditions. The protocol is based on the earlier developed chloroform/HCl extraction of pyocyanin from liquid cultures (Frank and Demoss, 1959). Swarming colonies together with the agar they occupy are split into two halves. Pyocyanin is extracted from one of them. Cells are collected from the other half and used to quantify total protein yield and normalize the estimated corresponding pyocyanin quantities.