Objective: Comparison of the results of microbiological RNA-probeanalysis after subgingival plaque sampling according to 2 differentstrategies. Methods: In 158 patients suffering from aggressiveor generalized severe chronic periodontitis clinical examinations wereobtained before (n=82) or after (n=76) combined mechanical and antibioticantiinfectious periodontal therapy. Subgingival plaque samples were obtainedfrom the 3 pockets with the deepest probing depths. Two sterile paper pointswere inserted simultanously in the periodontal pockets. One paper point fromeach pocket was put in a separate transport-vial, the second was pooled(MT3) with the two other paper points of a respective patient in atransport-vial. The content of each vial was analysed separately forActinobacillus actinomycetemcomitans, Tannerella forsythensis, Porphyromonasgingivalis, and Treponema denticola with a commercially available RNA-probetest. Results: The log-transformed number of bacteria was higherin pooled samples than the mean value of the results of the separate samplesfor all tested pathogens (P Conclusion: Pooling of subgingivalplaque samples increased the bacterial counts per analysis compared toseparate samples and thus may increase the probability to detect existingpathogens. However, this observation had no statistically significant effecton the detection frequency of the tested pathogens. Keywords: oral microbiology/diagnosis, sampling strategies, RNA-probes, generalised severe chronic periodontitis/aggressive periodontitis, subgingival plaque: Actinobacillus actinomycetemcomitans, Tannerella forsythensis, Porphyromonas gingivalis, Treponema dentico