Visualization of cryptococcal polysaccharide capsules capsular material of cryptococci displaces the colloidal carbon particles of the ink so that the capsule appears as a clear halo around the microorganisms against a black background
Used to stain pus, exudate, tissue, sputum and sediment of centrifuged urine and cerebral spinal fluid (csf) specimens
Particularly useful for csf specimens because cryptococcus neoformans is the most common cause of fungal central nervous system (cns) infections
Appearance of encapsulated yeast forms in an india ink smear from csf is diagnostic for cryptococcal meningitis
Positive (a 48-h culture of Cryptococcus neoformans ATCC 36556), negative (Candida albicans ATCC 10231) and stain (1 drop India ink + 1 drop sterile saline) controls should be run simultaneously with the organism or specimen being tested, Examine the reagent for signs of deterioration
