Definition ,Differences Between Thick Blood Smear and Thin Blood Smear

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A blood film—or peripheral blood smear according to wikipedia—is a thin layer of blood smeared on a glass microscope slide and then stained in such a way as to allow the various blood cells to be examined microscopically. Blood films are examined in the investigation of hematological (blood) disorders and are routinely employed to look for blood parasites, such as those of malaria and filariasis.

In the Laboratory,We have the Thin blood film and the Thick blood film.

Thin Films are similar to usual blood films and allow species identification, because the parasite's appearance is best preserved in this preparation.

Making a Thin film

Thick films allow the microscopist to screen a larger volume or proportion of blood and are about eleven times more sensitive than the thin film, so picking up low levels of infection is easier on the thick film, but the appearance of the parasite is much more distorted and therefore distinguishing between the different species can be much more difficult.

Thick Blood Smear

Here are the Difference Between Thin Film and Thick Film as applied in various laboratory bench unit

	Thick Blood Smear	Thin Blood Smear
	Thick blood smears are most useful for detecting the presence of parasites.	Thin blood smears helps to discover which species of parasite is causing the infection.
	A thick blood smear is a drop of blood on a glass slide.	A thin blood smear is a drop of blood that is spread across a large area of the slide.
	The blood films must be laked before or during staining to rupture all the RBC so that only WBC, platelets and parasites are visualized.	The purpose is to allow malarial parasites to be seen within the RBC and to assess the size of the infected RBCs compared to uninfected RBCs
	Thick smears allow a more efficient detection of parasites (increased sensitivity 11 times than thin smear).	Less sensitive than a thick film especially where there is a low parasitemia.
	It is not fixed in methanol.	It is fixed in methanol.
	Thick smears are mainly used to detect infection and to estimate parasitemia.	Thin smears allow the examiner to identify malaria species, quantify parasitemia, and recognize parasite forms like schizonts and gametocytes.