The following procedure is recommended primarily for the microbiological examination of process water. It is also applicable to slush pulp. This method is adequate for classical, heterotrophic cell counts of unencapsulated, planktonic microorganisms. This method will not give an accurate measure of the numbers of encapsulated, slime-forming cells or sessile microorganisms present. Because of the exacting technique required in microbiological procedures, reproducible results can be obtained only by a trained technician.