Mapping of RNA by a modification of the Berk-Sharp procedure: the 5′ termini of 15 S β-globin mRNA precursor and mature 10 S β-globin mRNA have identical map coordinates

We have used a modification of the Berk-Sharp technique to determine that the 5' termini of the mouse 15 S beta-globin precursor and the mature mRNA have identical map coordinates. The modification involves the use of 5' (or 3') terminally labeled probes; it allows the detection of the precursor in the presence of excess mature mRNA.