3.5. Concluding remarks about FISH

Preparing fine paraffin sections is the key to a successful FISH experiment. However, this step requires technical proficiency and practice. Therefore, whole-mount FISH (wFISH) (Koga et al., 2009) might be an attractive alternative. This technique does not require tissue sectioning, but a laser-scanning microscope is essential for analysis. In addition, wFISH has several other limitations, such as poor performance on large and thick specimens and vulnerability to autofluorescence. A combination of both FISH techniques would be optimal to obtain a comprehensive picture of the structural organization of microbial communities in the gut environment of bees and other insects.