A FLUORESCENCE-LABELING METHOD FOR SEQUENCING SMALL RNA ON POLYACRYLAMIDE-GEL

A practical fluorescence-labeling method for sequencing small RNAs by the traditional 'direct read out' on polyacrylamide gel electrophoresi s was established. The 3' terminus of RNA was oxidized into dialdehyde by sodium periodate and then labeled with fluorescein-5-thiosemicarba zide through the condensation reaction between carbazide and aldehyde. The fluorescence-labeled RNA was partially degraded enzymatically and fractionated by polyacrylamide gel electrophoresis. The fluorescent b ands were visualised by ultraviolet photography. A partial sequence of yeast 5S rRNA was determined. The result indicates that this method c an be used in sequencing small RNAs rapidly, conveniently and safely.