Abstract: A fluorescence in situ hybridization (FISH) procedure and solutions is provided. The entire FISH procedure is fast (15 minutes or less), with the hybridization step occurring in 5 minutes or less. The entire FISH procedure with digoxygenin- or biotin-labeled probes takes approximately 30 minutes. A formamide-free solution (dextran sulfate and glycerol) is provided. An additional solution (10% dextran sulfate and 20% formamide) is also provided. Additional solutions are provided for mRNA in situ hybridization whereby the process takes less than 24 hours.