Gram stain & morphology [GSM]
Published: July 8th, 2009
Revised: March 24th, 2023
This is an add-on test that provides further characterization of cultured bacterial contaminants according to Gram stain reaction and cell morphology. This test may be indicated when heterotrophic plate count (HPC) tests yield positive results. In this event, the laboratory will contact you and determine if you would like to add this level of characterization.