Quantification of picogram levels of specific DNA immobilized in microtiter wells

A non-radioisotopic and sensitive method for quantification of specific DNA immobilized in microtiter wells has been developed. This method is based upon the immobilization of DNA in microtiter wells and hybridization with biotinylated DNA probe which is followed by complexing with avidin-beta-galactosidase. By measuring fluorescence emitted from the hydrolyzed product by beta-galactosidase of 4-methylumbelliferyl-beta-D-galactoside, it has become possible to quantify a few picograms of specific DNA in DNA samples immobilized in plastic microtiter wells.