Optimisation of multiplex immunofluorescence for a non-spectral fluorescence scanning system.

The use of multi-colour immunofluorescence (IF) for immunophenotyping in formalin-fixed paraffin-embedded tissue sections is gaining popularity worldwide. This technique allows for the simultaneous detection of multiple markers on the same tissue section, thereby yielding more complex information than is possible by chromogenic immunohistochemistry (IHC). However, many commercially-available multiplex IF kits are designed for use in conjunction with a multispectral imaging system, to which many research groups have limited access. Here we present two 5-colour IF panels designed for T cell characterisation in human colorectal tissue, which can be imaged using a non-spectral fluorescence slide scanner with standard band-pass filters. We describe the optimisation process and the key considerations in developing a multiplex fluorescence assay, and discuss some of the advantages and disadvantages of using multiplex IF with a non-spectral imaging system.