The genetic dissection of any developmental processes requires mutagenesis protocols and the subsequent phenotypic screen of the established mutant strains. Whereas external structures such as the Drosophila cuticle are relatively easy to score without the need of further manipulations, the analyses of internal structures such as the nervous system often requires the use of antibodies to detect abnormalities. Here we describe an improved method to: (a) simultaneously collect Drosophila eggs from large number of fly strains, (b) process them fast for antibody staining and