3'-CYCLE-LABELED OLIGONUCLEOTIDES WITH PREDICTABLE LENGTH FOR PRIMER EXTENSION AND TRANSGENE ANALYSIS

Efficient labeling of short oligos at their 3'-ends was achieved throu gh polymerase chain reaction, The length of cycled-labeled oligos can be accurately predicted by omitting one or more dNTPs in the labeling step, Thus, labeled oligos can be simply column-purified, eliminating the need for tedious gel purification. We demonstrated the effectivene ss of this technique in determining the transcription start site of a given gene and in transgene analysis to differentiate the transcript o f an endogenous gene from that of an introduced homologous gene, This technique could be widely extended to other molecular biology applicat ions in which labeled oligos are employed.