Genomic indexing of 43 strains of Group II C. botulinum. An average linkage hierarchical clustering dendrogram of the C. botulinum strains was created in GeneSpring version 7.0 from microarray data using the Pearson coefficient correlation. Each row of the heatmap represents one strain and consists of a series of vertical bars which represent the CDS content of C. botulinum Eklund 17B (NRP). From left to right these bars are the chromosome from CB17B_0001 to CB17B_3470 then the plasmid from CB17B_P01 to CB17B_P54. The colour of each bar indicates the ratio of the signal from the test strain over that of the index strain. Where the signal from DNA binding is equal for both the test and control strains the bar is coloured yellow and where there is lower binding by the test strain the bar is blue. Where there is no probe the bar is white. The hierarchical clustering dendrogram has been coloured according to neurotoxin type: red =type B, blue =type E and green = type F. Strains were divided into three clusters using a distance of 0.5. Strain Eklund 2B appears slightly separate from the other Cluster 1 strains but this was a result of the culture used on the array lacking the 54 plasmid CDSs. Using only the chromosomal probes, Eklund 2B clustered with the other three strains in Clade 1.