The application of a photon-counting camera in sensitive, bioluminescence-enhanced detection systems for nucleic acid hybridization. Ultrasensitive detection systems for protein blotting and DNA hybridization, III.

A relatively simple, bioluminescence-enhanced detection system for nucleic acid hybridization, using alkaline phosphatase as a label, was described recently (Hauber, R. & Geiger, R. (1988) Nucl. Acid Res. 16, 1213). The principle of detection is as follows: Alkaline phosphatase releases D-luciferin (Photinus pyralis) from D-luciferin-O-phosphate. Liberated D-luciferin reacts with luciferase, ATP and oxygen with light emission. Light produced is measured with a very sensitive photon counting camera system (Argus-100), allowing the visualization and localization of the specifically bound alkaline phosphatase on nitrocellulose sheets. Under non-optimized conditions the limit of detection is at present about 30 pg of pBR322. A sulphonylated nucleotide probe was used for hybridization.