Restriction digests of the clone give the following sizes (kb): PstI--2.7; HindIII--2.7; EcoRI--2.7; ClaI--2.7. Escherichia coli transformed with this plasmid produce larger colonies when an insert is present in the polylinker than when there is no insert. Expression vector useful for construction of cDNA libraries and containing priming sites useful for sequencing. Permits visual detection of recombinants by beta-galactosidase alpha peptide complementation. pOM3 (ATCC 77222) and pOM4 (ATCC 77223) differ in the orientation of the polylinker. |