Remove the PBST and immerse the paraformaldehyde-fixed drosophila larval carcasses in a blocking agent for 40 minutes at room temperature. Replace the blocking agent with 200 microliters of the primary antibody diluted with 0.2%PBST. Leave the larvae to incubate at four degrees Celsius overnight.
The next day, wash the larvae with 0.2%PBST for 10 minutes. Next, remove the PBST from the tube and add 200 microliters of diluted secondary antibody. Incubate it at ambient temperature for 1.5 hours in the dark.
Introduce a nuclear dye such as TO-PRO R 3 iodide into the incubating tube for 30 minutes while staining the microtubules in the dark. Finally, rinse off the secondary antibody and the nuclear dye with 0.2%PBST for 10 minutes.