The modified API 20C system (Analytab Products, Inc.) containing 19 carbohydrate
assimilation tests was used to identify stock cultures of clinical isolates
and routine clinical isolates from the Mayo Clinic mycology laboratory. The
system provided correct identifications for 96% of the 505 organisms tested. The
API 20C represents a commercial system useful for the identification of yeasts
from clinical specimens. Although reliable, it is not a complete system and must
be used in conjunction with microscopic morphological features for definitive
identification. Since the system requires 72 h for identification, it is not designed
for the rapid presumptive identification of such organisms as Cryptococcus
neoformans; other biochemical tests must be used for this purpose.