Blood film preparation and staining procedures
Section snippets
Microscope Slides
Slides must be made from highest purity, corrosion-resistant glass; other material, such as plastic, is mostly not acceptable. Glass slides typically measure 75×25 mm; are approximately 1 mm in thickness; must be flat and free from distortions and ripples; and must be clear and colorless (water-white). For fluorescence microscopy applications glass must be used that does not show autofluorescence.
It is preferable to use precleaned slides, but at a minimum laboratories must ensure that slides
Blood Film Preparation Methods for Malaria Detection
It is recognized that morphologic identification of malaria parasites in (thick or thin) blood films is not the most sensitive method for malaria detection. Immunologic, biochemical, and molecular methods are often more sensitive but also much more expensive. For some time to come, the morphologic identification of malaria will remain in many laboratories as a major method for detection and monitoring of malaria. For morphologic detection of malaria parasites both regular and thick blood film
EVALUATION OF STAINED BLOOD FILMS
Macroscopically a properly prepared and stained blood film should be pink in its thin part and show a purple-blue tint in the thicker parts. Microscopically, the red blood cells should be pink and the nuclei of the white blood cells more purple than blue. There should be no or minimal precipitation and staining should be uniform throughout the slide. The blood cells should be free from vacuoles and other artifacts.
BIOHAZARD, SLIDE, AND REAGENT HANDLING
General precautions apply to handling of all patient specimens including blood films, whether air-dried, fixed, or stained.
Specimen Handling and Blood Film Preparation. The preparation of blood films need not be especially hazardous, but care must be taken on opening blood containers, especially when closed by a rubber stopper and not a screw cap. The removal of a rubber stopper frequently leads to droplet formation. This may be prevented by covering the stopper with a wipe or similar material,
USE OF BLOOD FILMS
Blood films can be used in a number of ways. Most are used for routine, clinical quantitative or qualitative analysis of formed blood elements. Its usefulness for morphologic screening is probably stronger than for purely quantitative purposes now that electronic white blood cell differential analysis has been much improved. Estimation of cell counts, such as platelets from a blood film, is highly subjective and shows poor correlation with analyzer results or reference counts (Houwen B,
Fixation and Staining
Optimal results are obtained by fixing and staining directly after the blood film is completely air-dried. Fixation of blood films before staining is recommended, although many laboratories have a practice of staining immediately after air-drying of blood films. This usually yields acceptable results. If slides cannot be stained immediately, however, fixation in methanol is necessary within 4 hours, but preferably less than or equal to 1 hour, after air-drying; otherwise, the plasma causes
References (24)
Erythrocyte morphology and “spinner” blood film preparations
J Histochem Cytochem
(1974)Quality control and the differential leukocyte count
Clin Lab Haematol
(1990)- et al.(1995)
- (1989)
- et al.(1975)
Devices for collection of skin puncture blood specimens
NCCLS Approved Guideline H14-A2
(1990)Evacuated tubes and additives for blood specimen collection
NCCLS Approved Standard H1-A4
(1996)The morphology of malarial parasites in thick blood film preparations. Part IV. The identification of species and phase
Trans R Soc Trop Med Hyg
(1940)An improved method for thick film preparation using saponin as a lysing agent
Clin Lab Haematol
(1997)- (1991)
Biohazard evaluation of laboratory hematology tests
ICSH reference method for staining of blood and bone marrow by azure B and eosin Y (Romanowsky stain)
Br J Haematol
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