Use of fluorescent substrate 4-MUP in the detection of biotin-labeled DNA probes.

To improve the sensitivity of detecting biotin-labeled DNA Probes, a new fluorescent substrate of alkaline phosphatase, 4-methylum belliferylphosphate (4-mup) was studied instead of conventional BCIP-NBT. The result of dot-blot hybridization demonstrates that this new substrate can be used for the colorimetric detection of biotin-labeled probes after hybridization to immobilized nucleic acids. The sensitivity is about one order of magnitude higher than that of BCIP-NBT system, and the time required for color development is very short, only about five min. It is suggested that the Bio-SA-Bio-AP-4-MUP colorimetric detection system can be widely used in gene diagnosis.