1. Dissect brains in Drosophila Ringers solution. 2. Fix 20'' (1hr max) in a 0.5ml microfuge tube with 5 formaldehyde-PBS on ice. 3. Rinse 2-3X with PBS (carefully remove solutions with drawn out pipets). 4. Block 1h @ room temperature (RT) on nutator. 5. Incubate overnight @ 4oC in primary antibody diluted in PBT. 6. Wash in 4-6 changes of PNT over a 2hr period @ RT. 7. Incubate 1-2h in secondary antibody @ RT on nutator. 8. Wash in 4-6 changes PBT (15'' each). 9. Mount in 80 glycerol-PBS. Drosohpila Ringers, per liter:6.5g NaCl0.14g KCl0.2 g NaHCO30.12g CaCl20.01g NaH2PO4 10X PBS1.3M NaCl 76.0 g NaCl0.07M Na2HPO4 9.94g Na2HPO4 (MW=142) H2O to 1L0.03M NaH2PO4 3.6 g NaH2PO4 (MW=120) Formaldehyde-PBS = 5 Formaldehyde (stock is 37) in 1X PBS PBT =1 BSA +0.1-0.5 Triton X-100 in 1X PBS PNT = 2 appropriate serum + 0.1 Triton X-100 in 1X PBS