Lab method
India ink preparation
Negative stain that reveals a capsule halo
High-yield clue
A clear halo around budding yeast in cerebrospinal fluid is the classic India ink clue for the Cryptococcus capsule.
Overview
A negative (background) staining concept where opaque ink particles cannot enter an organism's capsule, so an unstained clear halo appears around the cell against a dark field.
Classification
- Negative stain concept
- Wet-mount light microscopy
- Capsule visualization
- Non-specific method
Lab & identification clues
- Clear unstained halo against dark background
- Narrow-based budding yeast inside the halo vocabulary
- Capsule excludes ink particles
- Lower sensitivity than antigen testing vocabulary
Associations
- Cryptococcus in CSF study association
- Encapsulated yeast recognition
- Meningitis workup vocabulary
Commonly confused with
- Gram stain
- Calcofluor white stain
Frequently asked questions
What is India ink preparation?
A negative (background) staining concept where opaque ink particles cannot enter an organism's capsule, so an unstained clear halo appears around the cell against a dark field.
What is the high-yield clue for India ink preparation?
A clear halo around budding yeast in cerebrospinal fluid is the classic India ink clue for the Cryptococcus capsule.
What is India ink preparation associated with?
India ink preparation is associated with Cryptococcus in CSF study association, Encapsulated yeast recognition, and Meningitis workup vocabulary.
What is India ink preparation commonly confused with?
India ink preparation is commonly confused with Gram stain and Calcofluor white stain.
Original concept summary for coursework. Sources checked: OpenStax Microbiology 2e and NCBI Bookshelf Medical Microbiology; reviewed 2026-06. Describes vocabulary and interpretation concepts only; not a lab protocol and not for handling specimens or identifying patient isolates.