Among other things, this disclosure provides a method of detecting a target nucleic acid. Aspects of the method include: (a) obtaining a labeled nucleic acid probe that is complementary to a target nucleic acid, wherein the probe comprises a capture tag; (b) hybridizing the probe with the target nucleic in a fixed cell, in situ, to produce a duplex; (c) linking the probe in the duplex to a peroxidase conjugate via the capture tag to produce a peroxidase-labeled duplex; and (d) incubating the peroxidase-labeled duplex with a peroxidase substrate, wherein the peroxidase activity of the peroxidase conjugate catalyzes deposition of the substrate in the vicinity of the duplex, thereby producing a detectable signal.