I'm currently working with mouse peripheral blood, but several issues came out every time. Actually we are using as collection site the tail, blood is drip in eppendorf containing EDTA and inverted several times for better mixing. When the samples arrives in my lab, we use to gently invert again the eppendorf, for better distribution of anticoagulant, and 5ul of blood is placed on the slide. with another slide the smear is performed, the angle of smear is small, to have a thin smear and the velocity is low, to obtain a good distribution of blood all over the glass. Smears are air dried and stained with May-Grunwald-Giemsa by lab technician of Hematology dept. the next day.

The problems are related to frequent burst of WBCs and RBCs hemolysis, that occurs almost every time... but we cannot understand the causes.

Thanks for every suggestion