It depends on exactly you want to do, but a good place to start would be
using membrane filtration.
For bacteria, if you are looking for specific organisms numbers, filter and
place the membrane on a selective medium. For detection of pathogens eg
Salmonella, since they will be present in probably small numbers, add the
membrane to an enrichment broth and sub culture to a selective medium. If
you are simply looking for numbers, but are unconcerned as to the identity
of the organisms, try using a pour plate with yeast extract agar.
I haven't tried isolating fungi from water, but I would think again
filtration and placing the membrane onto a suitable medium such as
sabourauds would work.
Parasites can be problematic depending on what you are looking for,
Cryptosporidium being a case in point, but if you are looking for something
along the lines for Giardia or Entamoaba filter your water and wash your
membrane in about 5 - 10 ml of formal saline. You can either examine the
whole sample or concentrate it further.
Paul and Kimberly Liska <pliska at istar.ca> wrote in message
news:8J5d3.13$gs.165603 at NewsRead.Toronto.iSTAR.net...
>> I am wondering if anyone can provide me with a good method or technique
> screening a sample such as water for bacteria, fungi, and parasites. Thank