['To evaluate the discriminatory power and usefulness of arbitrarily primed-polymerase chain reaction (AP-PCR) characterization of leptospires with M16 primer.', 'AP-PCR fingerprints of 20 reference strains of Leptospira representing 20 different serovars belonging to seven genospecies (Leptospira interrogans, 11; L. noguchii, 2; L. borgpetersenii, 1; L. santarosai, 2; L. biflexa, 2; L. kirschneri, 1; L. weilii, 1) were generated by employing M16 primer. Fingerprints generated with this primer were compared with those generated with two other commonly used primers PB1, and L10. An attempt was also made to type 20 leptospiral isolates with the M16 primer.'] Does a 22-mer primer enhance discriminatory power of AP-PCR fingerprinting technique in characterization of leptospires?