Alcian blue staining
Cryptococcus can be stained using Alcian blue because of the large amount of acidic
mucopolysaccharide involved in its capsular. After staining, the capsular is dark blue and the
thallus is light blue, while the surrounding inflammatory cells are not colored. Thus, the staining
is very clear, even with low amounts of cryptococcus. The positive rate is approximately
80% (He and He, 2007). In this study, the positive rate at first detection was 67.7%, with a
total positive rate of 80.6%. The running off of CSF, misdiagnosis for a small amount of cryptococcus,
and non-staining of cryptococcus with deletion of capsular are the main causes of
false-negative results.