The Comparison of the Efficacy of Various Fixatives on Diverse Staining Methods of Giardia lamblia Cyst

The definite and exact diagnosis of protozoa is possible using high magnification objective lenses, provided that suitable stained smears are prepared. Therefore, the appropriateness of both fixative and staining methods to the species of parasite, which is the main objective of this study, is important. In this study, five various fixatives including (Merthiolate iodine formalin) MIF, (Sodium acetate-acetic acid formalin) SAF, (Polyvinyl alcohol) PVA, formalin and schaudinn and four types of stains including Hematoxylin I, Hematoxylin II, Trichrome and Carbol-fuchsin were prepared using standard procedures. After the smears of stool samples containing Giadria lamblia cyst were prepared and kept for 24 h in various fixatives, the study was carried out using the four above-mentioned stains by changing the ingredients and time as well as by repeating the experiments. After fixing and staining all the smears in identical conditions along with the implementing interferences in the staining process, the following results were eventually obtained considering the morphologic indexes and negative and positive scores (from 1 to 20): formalin with 17 scores in hematoxylin I staining, formalin and SAF with 15 and 14 scores, respectively in Hematoxylin II staining, MIF with 13 scores in Trichrome staining and SAF, PVA, MIF with 11.5, 11.5 and 11 scores, respectively in carbol-fuchsin staining were found to be the best fixatives. Hematoxylin I staining using formalin fixative with 17 scores showed the best result while the maximum score for Carbol-fuchsin staining was 11.5 showing a necessity for more expenditure, time and expert cooperation to reach ideal results.