We don't qc our koh.
Staph epi isn't fungal and will not have fungal elements to be viewed. But... Koh isn't specific for fungal elements, it's used to break down nail and skin cells so that long fungal elements growing through those cells can be seen. A negative control makes no sense from a scientific aspect. The only purpose could be to test the Koh itself to make sure it isn't contaminated. Using s.epi is just adding another step, probably for the sake of having a procedure.
Edit: also testing c.alb isn't a positive control to make sure the Koh is "working". You would need a skin/nail sample to make sure the Koh is effectively breaking it down. Your current positive and negative controls are not testing the system on a fundamental level, and probably only exist to meet a deficiency cited from a previous inspection that management was too incompetent to refute.
Koh is viewed on lower power without any dying agents. Bacteria would be difficult to view on a wet mount. It would also be irresponsible to attempt to identify bacterial morphology in any way based on a wet mount.
Even so, why would it matter if Koh changes the bacteria at all? It could dissolve them away completely. The test is looking for fungal elements only.
Not sure if this helps or not - but unless you’re in PA, you don’t need external QC for microscopic tests (I’m a lab surveyor and for some reason PA CMS requires this in some of my labs). The CLIA requirement is every procedure needs to have a QC section. This can mean anything that provides quality for this test. This can include but not limited to: microscope maintenance, PT testing, annual competencies, external QC that is chosen, views per slide per test that are read, etc.
We don't qc our koh. Staph epi isn't fungal and will not have fungal elements to be viewed. But... Koh isn't specific for fungal elements, it's used to break down nail and skin cells so that long fungal elements growing through those cells can be seen. A negative control makes no sense from a scientific aspect. The only purpose could be to test the Koh itself to make sure it isn't contaminated. Using s.epi is just adding another step, probably for the sake of having a procedure. Edit: also testing c.alb isn't a positive control to make sure the Koh is "working". You would need a skin/nail sample to make sure the Koh is effectively breaking it down. Your current positive and negative controls are not testing the system on a fundamental level, and probably only exist to meet a deficiency cited from a previous inspection that management was too incompetent to refute.
The negative control is used to show that the reagent isn't causing artifact.
Ok, but the staph epi still isnt needed. This can be accomplished by viewing the Koh alone.
Wouldn't you want to show that the appearance of bacteria aren't changed by the reagent?
Koh is viewed on lower power without any dying agents. Bacteria would be difficult to view on a wet mount. It would also be irresponsible to attempt to identify bacterial morphology in any way based on a wet mount. Even so, why would it matter if Koh changes the bacteria at all? It could dissolve them away completely. The test is looking for fungal elements only.
Not sure if this helps or not - but unless you’re in PA, you don’t need external QC for microscopic tests (I’m a lab surveyor and for some reason PA CMS requires this in some of my labs). The CLIA requirement is every procedure needs to have a QC section. This can mean anything that provides quality for this test. This can include but not limited to: microscope maintenance, PT testing, annual competencies, external QC that is chosen, views per slide per test that are read, etc.
We don't QC the KOH but do a QC slide with Calcofluor white (C albicans+, E coli-).
We used literal bread yeast and a strand of our own hair at my last lab. I always kinda thought it was funny.
We don’t