ABSTRACT:Ultrasensitiveandspecificinsituimagingofgeneexpressionisessentialformolecularmedicineandclinicaltheranostics.Wedevelopanovelfluorescenceinsituhybridization(FISH)strategybasedonanewbranchedhybridizationchainreaction(bHCR)forefficientsignalamplificationintheFISHassayandaligase-me