Can I use CST antibodies for fluorescent detection in FFPE tissue?

At CST we do not typically validate antibodies using indirect fluorescent detection in formalin fixed, paraffin embedded (FFPE) tissue. If a product is recommended for use in chromogenic IHC, denoted as IHC-P on the product page, there is a chance that it will also work with indirect fluorescent detection. The main challenges of using direct or indirect fluorescent detection in FFPE tissue is the increased autofluorescence levels caused by formalin fixation and the relative lack of signal amplification. Targets expressed at moderate to high levels are most likely to work well with fluorescent detection. For indirect fluorescent detection in FFPE tissue we recommend following parts A-C of the IHC protocol found on the antibody product page along with the primary antibody diluent recommended in part D.6. After antigen unmasking, proceed to part C of the Immunofluorescence Protocol found here.

For targets expressed at lower levels, signal amplification may be required. Tyramide signal amplification (TSA) is generally regarded as the simplest way to increase signal intensity when using a fluorescent readout. CST has designed a TSA-based multiplex IHC protocol (found here) that can be amended for single stains if desired.

Last updated: September 12, 2024