India ink prep
The India ink prep can provide both rapid detection and presumptive identification of Cryptococcus neoformans (or Cryptococcus gattii - see a further explanation in the next topic section). The capsule of Cryptococcus will exclude the ink particles so that a characteristic halo forms around the yeast cell (indicated by the arrows in the image below). Budding forms should be observed to confirm a positive smear. However, this test is not as sensitive as the cryptococcal antigen test. India ink preparations are negative in at least half the cases of cryptococcal meningoencephalitis, and early in the disease, inflammatory cells may not be present.
