FIELD’S STAIN SOLUTION A

Field’s Stain Solution A is a stain for microscopic examination of blood films. It aids in the visualisation of spirochaetes, protozoa and other organisms in the blood. It is especially useful in screening thick films of blood for malarial parasites.
The field’s stain contains methylene blue and eosin. The mixture of basic and acidic dyes results in differential staining. These dyes bind to different cell components and give different colours. Acidic components such as the nuclear material, absorb the blue to purple shades of the basic dye and are called basophilic. Basic components, including parts of the cytoplasm, react with the acidic dye and appear eosinophilic or acidophilic. Both dyes can be taken up by neutral components.
Methanol is the fixative which helps to preserve the specimen during staining. The product appears as a clear blue-violet solution and passes the specified sensitivity test.
Preparation Blood films for malaria examination should be made soon after collection, ideally within 3-4 hours. Methanol for fixation must be anhydrous as moisture may impact staining quality. Clean slides should also be clean, as detergent residues can interfere with staining of the red blood cells. Thick films may occasionally develop stain residue or interference from lysed red cell material.

Used for staining blood films to visualize spirochaetes, protozoa, and malarial parasites through differential cellular staining.