A system for making strand-specific M13 hybridization probes

A system for making strand-specific M13 hybridization probes 

Full experimental details are given in Hu and Messing s paper and are not repeated here. 

The stability of the partially double stranded probe means that, under the conditions described in their paper it can be used to probe other M13 recombinants. Since the viral strand in all M13 clones is the (+) strand and since the labelled (-) strand does not dissociate from its template, hybrids are only formed when the separate Ml 3-derivatives contain regions of complementary single stranded insertions. M13 recombinants containing long (3 kb) inserts derived from genomic DNA can therefore be probed with M13 recombinants containing, for example, cDNA sequences obtained by reverse transcription of a mRNA. 

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