I have recently started working on quantifying the virulence factor of Pseudomonas aeruginosa. In winters when there was a reducing environment, I was getting a greenish tint in my bacteria. Now in the summers, I am getting sticky yellow bacterial culture when I am plating them on microtitre plates or test tubes for biofilm assay. I am following the protocol of chloroform and HCl extraction with just 2 ml of culture. But I am not getting any kind of pink color or color upon adding HCl and centrifugation. Then how can I be sure that the thing I am getting after the protocol is pyocyanin or not? At last, I am getting faded yellow color transparent liquid. If anyone is working on pyocyanin or other pigments like pyoverdin or rhamnolipid, please do connect [email protected]