Confirmation of the ΔpurD gene deleted Br.abortus mutant. A, PCR for Br.abortus (498 bp). Line M showed 1Kb ladder; Line 1 1st Br. abortus transformed colony DNA; Line 2 2nd Br. abortus transformed colony DNA; Line 3 is the positive control. B, PCR for KM confirmation (986 bp). Line M showed 1Kb ladder; Line 1 ΔpurD deleted mutant DNA; Line 2 is the positive control. C, PCR for detection of purD gene (1280 bp). Line M showed 1Kb ladder; Line 1 ΔpurD deleted mutant DNA; Line 2 is the positive control.