AluI restriction endonuclease digestion of PCR products of C. trachomatis-positive clinical samples visualized by silver staining on polyacrylamide gel electrophoresis. Lanes: M, molecular size marker; 1, standard serovar D; 2, clinical sample showing banding pattern matching that of standard serovar D; 3, standard serovar E; 4, clinical sample showing banding pattern matching that of standard serovar E; 5, standard serovar F; 6, clinical sample showing banding pattern matching that of standard serovar F; 7, standard serovar I; 8, clinical sample showing banding pattern matching that of standard serovar I; 9, uncut amplicon.