Operation method of indole experiment

Inoculate bacteria in peptone water culture medium at 37℃

Add 1 ~ 2ml diethyl ether to the culture solution, and let it stand for a while, and the diethyl ether layer floats on the culture solution. At this time, slowly add 5 ~ 10 drops of indole reagent along the tube wall (do not shake the tube after adding indole reagent to avoid damaging the ether layer and affecting the observation of the results). If there is indole, the ether layer is rosy, which is a positive reaction of indole test, otherwise it is a negative reaction, and the positive reaction is "+"and "".