Comparison of May-Grünwald Giemsa staining methods for manual microscopy of blood smears

The manual differential count of leukocytes is a common analysis in the hematological laboratory. It is used for morphological assessment of the blood cells and can get valuable information according to diagnosis of hematological diseases. The microscopy assessment is dependent of a good staining result of the blood smear in order to get the best conditions to differentiate the different cell types and detect morphological or pathological findings.The aim of this study was to determine if it was possible to change the staining method without any compromises to the quality of the staining results. For this study 25 whole blood samples were collected, and blood smears was made and stained with four different staining protocols, including the one currently used in the routine practice at laboratoriemedicin Sundsvall. The samples were examined by three biomedical scientists and the staining quality of the cells was graded on a four-point scale. The statistical results with Friedmans and Wilcoxons signed-rank test showed differences between the methods on the nuclear and cytoplasm of lymphocytes and the nuclear of monocytes and neutrophils. The recommended staining protocol from the manufacturer was the method that had highest frequency of statistically significant differences compared to the other methods for those cell types. The differences were in favour for the other methods, and the current method showed the best performance. In conclusion it’s not recommended to continue the study with the manufacturer´s staining protocol, but its valuable to continue compare the best performed staining protocols.