Conclusion
The development of a more holistic mechanistic model allows the
maximization of the FISH’s efficiency helping in the optimization of
probe design and probe concentration. It is however apparent from this
work that many of the characteristic time values obtained lack strong
experimental support. In future works, these parameters could be further
assessed experimentally, using fluorescent microscopy techniques such as
fluorescence recovery after photobleaching (FRAP). With the current
data, it was estimated that for bacterial cells the limiting step for
diffusion is likely to be the peptidoglycan layer, whereas for animal
cells the limiting step is more likely to be the diffusion of the probe
through the bulk medium followed by the diffusion through the lipid
membrane. The information provided here may serve as a basis to optimize
FISH protocols and as a conceptual background for the interpretation of
FISH as a specific case of a diffusion-reaction process.