Evaluation of Trichrome-PLUS™ Stain, a New Permanent Stain and Procedure for Intestinal Parasites in Fecal Specimens

© Copyright 2003 by Dr. Omar M. Amin
Parasitology Center, Inc.
903 South Rural Rd., #101-318,
Tempe, Arizona, USA 85281
(Explore Issue: Volume 12, Number 2)

Summary:
Heavy metal based low-viscosity polyvinyl alcohol (LV-PVA, ZNPVA, Z-PVA, PVA-Hg and modified PVA) have been widely used by clinical laboratories to perform permanent stained smears from fecal specimens to demonstrate the presence of intestinal parasites. Regulatory, environmental concerns and costs have forced laboratories to consider alternative fixatives for these procedures. We compared the Trichrome-PLUS™ stain permanent stained smears, taken from the concentrated fecal fixed specimen using the Proto-fix™ fixative with CONSED™ Sedimentation Reagent (viewed as wet mount), at the Parasitology Center, Inc. (PCI) in Arizona. Test results of the same concentrated specimens were compared using the wet preparation against the permanent stained smear. The number and identity of parasite species, fungi, blood cells and crystals were identical in all 61 tests compared. The intensity of infection measured on a scale of 1 (rare) to 4 (many) was identical in 75% of the 61 samples tested. Differences in intensity levels, in the remaining 25% of the specimens, were variable by only one degree of intensity. Our data suggests that the Trichrome-PLUS™ stain provides an ideal system to obtain a permanent record of findings using the Proto-fix™ fixative and CONSED™ Sedimentation Reagent.