Tyramide Signal Amplification (<scp>TSA</scp>) Systems for the Enhancement of <scp>ISH</scp> Signals in Cytogenetics

Abstract

This unit provides a series of techniques that dramatically improve the sensitivity of direct and indirect in situ detection. TSA is a peroxidase-based signal amplification system which is compatible with all in situ hybridization as well as immunocytochemical detection systems. The assay is performed on a glass slide and combines the use of fluorescent probes in either direct or indirect format using either an enzyme-labeled streptavidin or antibody. Protocols are provided for brightfield and fluorescent detection of single DNA targets, DNA or RNA in cultured cells, multitarget detection for DNA/RNA and DNA and RNA. In addition a protocol is included for the TSA plus system, a DNP-based detection system using horseradish peroxidase and alkaline phosphatase.