Hybridization to tissues on slides or coverslips for whole-mount FISH in Drosophila

Many Drosophila tissues (other than embryos or egg chambers) are too large, delicate, transparent, or buoyant for manipulation in suspension. Tissues such as spermatocytes, spermatids, and imaginal disks are difficult to handle in suspension and are more appropriately fixed on slides or coverslips for whole-mount fluorescent in situ hybridization (FISH). As described in this protocol, the hybridization reaction can be performed in Coplin jars (which require 50-60 mL of solution to cover the sample), larger staining jars (which require 200 mL), or coverslip-staining jars (which hold ∼7-10 mL). Following hybridization, staining with antibodies or other detection reagents can be performed in a humid chamber and staining solution can be applied directly to the tissue.