CMS SOM App. C, Tag D5527

(c) Each month of use, the laboratory must check permanent stains using a fecal

sample control material that will demonstrate staining characteristics.

Interpretive Guidelines §493.1264(c)

The fecal sample control may contain either parasites or added leukocytes sufficient to

demonstrate staining characteristics. A commercially prepared quality control slide for

intestinal parasites is also an acceptable control for checking permanent stains.

While a wet mount preparation may not be sufficiently sensitive to detect small numbers

of ova or parasites in fecal specimens, or to render a final species identification, the

regulations do not require use of concentrated and permanent stain techniques to identify

fecal parasites. It is the laboratory’s responsibility to ensure that it can accurately and

reliably identify the organisms it claims to be able to identify. Use D3007 and/or D5411

as applicable. Upon request, the laboratory must specify the method employed by the

laboratory for screening fecal specimens and provide information to clients on the test

report that may affect the interpretation of test results. Use D5807 and/or D5809 as

applicable.

The working iodine solution is stable for approximately two weeks. If the laboratory

does not prepare fresh working iodine solution at least every two weeks, it must ensure

that the iodine solution has not deteriorated by observing positive clinical specimens or

formalin-fixed specimens. Use D5417. Protozoan cysts stained with iodine contain

golden yellow cytoplasm, brown glycogen material and have refractile nuclei.

§493.1264 Standard: Parasitology.

(d) The laboratory must document all control procedures performed, as specified in

this section.

Interpretive Guidelines §493.1264(d)

QC records should include lot numbers, date prepared/opened, expiration dates, the actual

measurements, reactions, and/or observations and demonstrate that controls were tested

and acceptable when shipments of reagents, disks, stains, or antisera for identification

systems were opened or when the laboratory prepared these materials. QC records

should also include documentation of the measurements and calculations for calibration

of each objective (low, high, oil immersion) of the ocular micrometer, and demonstrate

that permanent stain controls were tested with a fecal sample control material each month

of use.