Indian Ink Stain Test
2,250 Kshs | Home Collection Available
Synonyms
Cerebrospinal fluid culture, Cryptococcus antigen titer
Purpose
Clinicians use the Indian Ink Stain Test as a microscopic technique to detect Cryptococcus neoformans, an encapsulated yeast, especially in cerebrospinal fluid (CSF) samples. They primarily use this test to diagnose cryptococcal meningitis a life-threatening fungal infection that often affects immunocompromised individuals, particularly those with HIV/AIDS.
The test helps in the rapid identification of Cryptococcus by visualizing its thick capsule, which appears as a clear halo against a dark background when mixed with Indian ink. Early detection is critical for prompt antifungal treatment, which can significantly reduce complications and mortality.
The tests can be done alongside Cryptococcal Antigen (CrAg) Test, CSF culture, CSF analysis, and HIV test.
Patient Preparation
The patient might be asked to empty their bladder and bowels before the test.
Samples
2 – 4 ml Fungal specimen collected in a Clean sterile tube. A lumbar puncture is used to collect CSF, and the patient is required to stay very still while the fluid is being withdrawn. Maintained at room temperature.
Reference Range
No Cryptococcus identified
Results Turnaround
1 – 2days after receipt of samples.
Diseases / Diagnostic indicators
The Indian Ink Stain Test provides a quick visual indication of the presence of Cryptococcus neoformans in cerebrospinal fluid (CSF) or other samples.
Positive Result:
- Cryptococcus neoformans appears as round yeast cells surrounded by a clear halo (capsule) against the dark background of the ink.
This confirms a cryptococcal infection, most commonly cryptococcal meningitis, especially in patients with HIV/AIDS or weakened immune systems.
A positive result usually prompts immediate antifungal treatment and further confirmatory testing (e.g., CrAg test, culture).
Negative Result:
No encapsulated yeast is seen. This may suggest:
- No cryptococcal infection.
- Very low levels of the organism (early or localized infection).
- Poor sample quality or inadequate technique.
In such cases, additional tests like a Cryptococcal Antigen test or CSF culture are often recommended to rule out or confirm the diagnosis.
This test plays a critical role in the early detection of life-threatening fungal infections, especially in high-risk individuals. For more on Indian Ink Stain Testing, read this study.