Microbial analysis of Purified and Raw watet

During microbial analysis of Raw and purified water , how much quantity of water is to be enriched for pathogen testing??? if anyone can provide any reference ??

you can use USP compendia

i couldn’t find specific quantity to be taken in USP also

Minimum quantity of RW,PW is 01ml , for pathogens 100 ml
Salmonella only 01 ml

is it written somewhere 100 ml for pathogens ??

u can read USP 60 and 61 .