找出有错误的语法进行更改Germ-free GF flies were generated exactly as described previouslyref To generate GF flies eggs were washed twice with about 33 sodium hypochlorite solution and water respectively Using a s

Germ-free (GF) flies were generated exactly as previously described (ref). To generate GF flies, eggs were washed twice with a 3.3% sodium hypochlorite solution and then with water. Using a sterilized paintbrush, eggs were transferred from the brush to the sterile diet individually or in small batches. Aim for 30-50 eggs per vial. Leave the caps loose to allow oxygen to enter the tube.