The Microbial Ecology Group of Munich's University of Technology has recently launched probeBase, "a comprehensive database containing published rRNA-targeted oligonucleotide probe sequences, DNA microarray layouts and associated information." Users may search for sequences by target organism, which "can assist in the development of new rRNA-targeted oligonucleotide probes for fluorescence in situ hybridization (FISH)," or by probe name for rapidly retrieving published probes targeting desired sequences without prior phylogenetic analysis. Researchers are encouraged to submit new or missing probes in efforts to keep probeBase as up-to-date as possible. A list of RNA-related links is also provided.