COMMERCIAL LABS: HOW ACCURATE ARE THEY?

The authors conducted a blind survey of 16 commercial laboratories in order to evaluate their ability to test for Giardia and Cryptosporidium using the American Society for Testing and Materials (ASTM) method. After filters were spiked with approximately 740 Giardia cysts and Cryptosporidium oocysts or 500 cells of the alga Oocystis, they were sent to the laboratories for analysis