Evaluation of a new system for the fixation, concentration, and staining of intestinal parasites in fecal specimens, with critical observations on the trichrome stain.
Proto-fix (Alpha-Tec Systems, Inc., Vancouver, WA) is a new single vial, environmentally safe, parasitology (pathogenic and nonpathogenic protozoans and helminths) fixative and transport solution. It is used in conjunction with a new concentration/sedimentation reagent, CONSED, (Alpha-Tec Systems, Inc. Vancouver, WA) as a replacement to the formalin-ethyl acetate (FEA) concentration procedure using Lugol's iodine. The newly adopted procedure was tested against the FEA concentration samples using split proficiency testing samples supplied by the American Association of Bioanalysts (AAB). Routinely, patient samples collected, fixed, and transported in Proto-Fix were processed and tested at Diagnostic Labs, Inc. (DLI), Phoenix, AZ. Detected parasites were documented using a video camera-printer system attached to the optical equipment. The quality of the fixative and stain were found to be superior to that of the FEA-Lugol's method and the yield of detected parasites was considerably higher. Eighty-five percent of 39 unknown parasite species tested were correctly detected using the Proto-fix-CONSED system compared to 46% using the FEA-Lugol's method. Of all the other methods and stains used at DLI, the trichrome stain (a popular modification of Gomori's trichrome stain for tissue sections) was found to be least reliable.
Amin
O M
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Diagnostic Labs, Inc, Phoenix, AZ 85018, USA. omaramin@aol.com
D000818:Animals; D001391:Azo Compounds; D004801:Eosine Yellowish-(YS); D056890:Eukaryota / Q000302:isolation & purification; D005069:Evaluation Studies as Topic; D005243:Feces / Q000469:parasitology*; D006373:Helminthiasis / Q000175:diagnosis / Q000469:parasitology; D006376:Helminths / Q000254:growth & development / Q000302:isolation & purification; D006801:Humans; D007411:Intestinal Diseases, Parasitic / Q000175:diagnosis* / Q000469:parasitology; D008739:Methyl Green; D010274:Parasitology / Q000379:methods*; D011528:Protozoan Infections / Q000175:diagnosis / Q000469:parasitology; D011933:Reagent Kits, Diagnostic; D013048:Specimen Handling
D001391:Azo Compounds; D011933:Reagent Kits, Diagnostic; C017768:trichrome stain; D008739:Methyl Green; D004801:Eosine Yellowish-(YS)