An ideal aspirate is of creamy consistency with numerous cells suspended in a small amount of tissue fluid without admixture with blood. Such aspirates are smeared immediately using another slide or cover slip or with the needle itself and dropped into the fixative. At the beginning of the smearing process, while the material is still in a drop on the slide, the surface area for evaporation is relatively small and hence a short delay will not cause significant air-drying. Once the smear has been made, the surface areas are greatly increased and the thickness of the smear is greatly diminished. Thus from the instant the smear.
