Hi Mari

we've had excellent results using the NEN TSA kit in its simplest form: primary
Ab, followed by horseradish peroxidase conjugated secondary Ab, then the
FITC-tyramide.  One primary Ab we had gave a very weak signal using biotinylated
secondaries and Alexa 488 streptavidin:  with TSA this was one of the brightest
fluorescent signals we've imaged in tissue sections.

hope this helps

Martyn Evans
SmithKline Beecham
Harlow UK