Methods are provided for highly sensitive and rapid in situ detection of
a nucleic acid analyte of a known sequence. The method employs oligonucleotide
probes in a series of optimized steps to amplify a signal and decrease background.
Sensitivity is enhanced such that the method can detect as few as 1-2 copies of
nucleic acid analyte per sample, the sample containing a cell, tissue or similar
biological material. Methods of detecting and identifying the position of the nucleic
acid analyte in a cell are also provided.