A new, very sensitive, bioluminescence-enhanced detection system for protein blotting. Ultrasensitive detection systems for protein blotting and DNA hybridization, I.

A relatively simple, very sensitive bioluminescence-enhanced detection system for protein blots is described. The method utilizes antibodies conjugated with alkaline phosphatase. The alkaline phosphatase then takes part in a reaction by releasing D-luciferin (Photinus pyralis) from D-luciferin-O-phosphate. Liberated D-luciferin reacts with luciferase, ATP and oxygen with light emission. The light is detected by a sensitive photographic film, thereby permitting the visualization of the alkaline phosphatase-conjugated antibodies. Under non-optimized conditions the limit of detection is at present 5 to 50 pg of protein, corresponding e.g. to 30 to 300 x 10(-18) mol of rabbit immunoglobulin G. The detection system is therefore 100 times more sensitive than other systems used at present.