Multilocus allele analysis of B. abortus field strains. Graphical representation of the alleles generated by fluorescent tagged-PCR amplification of the genomic DNA of Brucella abortus biovar 1 field isolates. Each lane is the compilation of data from the independent amplification of each of the eight VNTR loci. Among cattle isolates, the samples are labeled with the state of origin; independent herds are indicated by an arbitrary number; and samples from the same herd are boxed. Each isolate was obtained from a single animal.