Results are summarized in figure 4. As shown above, LSplex of S. aureus DNA allowed unambiguous species identification and discrimination from coagulase negative Staphylococci. Hybridization profiles of LSplex products Eltanexor ic50 corresponded very well with the expected hybridization profiles from genomic DNA (not shown). Amplified S. epidermidis DNA hybridized specifically selleck chemicals to S. epidermidis capture probes and showed no cross-hybridizations with S. aureus capture probes as well as with capture

probes of other coagulase negative staphylococci. Similar results were obtained with LSplex products of S. pneumonia DNA leading to clear-cut species identification and differentiation from all other Streptococci species. LSplexed E. faecalis DNA displayed high specificity to probes of E. faecalis, showing no cross hybridization with

the closely related species E. faecium. The same was observed in hybridization experiments with P. mirabilis DNA. Notably, LSplex products of 10 ng C. albicans DNA produced highly specific signals, with 4 to 5-times greater fluorescence intensity than those produced by 2 μg of genomic DNA. Figure 4 Specific detection of microbial DNA by LSplex amplification. Hybridization profiles generated selleck screening library by analysis of LSplex amplified products shown as columns (S. aureus, E. coli, S. pneumonia, E. faecalis, P. mirabilis, S. epidermidis, K. pneumoniae, C. albicans and P. aeruginosa). Each row represents an individual capture probe of the microarray, grouped by species or genus specific regions (see Additional Axenfeld syndrome file 2) as indicated in the left column. The boxes represent the positive hybridization signal of bacterial DNA (in colour) or absence of hybridisation (in white) with individual capture probes. Application of LSplex for microbiological diagnostics In order to demonstrate benefits of LSplex for the microarray-based detection of pathogens in clinical specimens we analysed cotton swabs taken from patients with superficial wounds. Such swabs represent one of the most frequent materials

processed by microbiological diagnostics. Swabs from superficial wounds contain one or more pathogens, normal skin flora and few human cells. The number of bacteria on swabs is usually low, so that time consuming amplification via subculture on microbiological media is required. DNA was isolated from three swabs taken from the same patient. DNA preparations were pooled and divided into two samples of approximately 20 ng each. One sample was subjected to LSplex (800 primer pairs). Other labeled directly prior to hybridization with the microarray. A typical hybridization pattern is depicted in figure 5. The directly labeled DNA hybridized only with 16S RNA probes (positive controls) indicating the presence of bacterial DNA in the sample (Fig. 5).