A DOUBLE STAINING TECHNIQUE USING 5-BROMO,4-CHLORO-3-INDOLYL-BETA-D-GALACTOPYRANOSIDE (X-GAL) AND IMMUNOPEROXIDASE IN WHOLE DROSOPHILA EMBRYOS

We have developed a double staining method using 5-bromo,4-chloro-3-indolyl-beta-D-galactopyranoside X-gal and immunoperoxidase for whole Drosophila embryos. The dechorionated embryos are fixed in heptane saturated with 4% formaldehyde, then in heptane and 50% methanol. Fixed embryos are devitellinized with a tungsten needle and processed for immunoperoxidase staining immediately prior to peroxidase color development. The embryos are stained with X-gal, then peroxidase staining is resumed. This procedure enables us to observe cells stained with both X-gal and a specific antibody in whole embryos.