Definition

1. Noun:
   • A fluorescent dye used as a biochemical marker: Fluorescein isothiocyanate (FITC) is a synthetic organic compound that emits a bright green-yellow fluorescence when exposed to blue light. It is a derivative of fluorescein, modified with an isothiocyanate reactive group.
   • A common labeling reagent in biomedical research: Its primary use is to chemically conjugate (bind) to proteins, especially antibodies, enabling their visualization under a fluorescence microscope.

Usage

• FITC is used to tag molecules so scientists can track their location and movement within cells or tissues.
• It is a standard tool in techniques like immunofluorescence, flow cytometry, and fluorescence microscopy.

Examples

• Noun:
  • The antibody was labeled with fluorescein isothiocyanate for the imaging experiment.
  • FITC's emission spectrum is well-suited for standard fluorescence filter sets.

Advanced Usage

• "FITC-conjugated antibody": An antibody that has been chemically linked to FITC, allowing researchers to see where the antibody binds.
  • We used a FITC-conjugated antibody to detect the presence of the viral antigen.
• "FITC channel": Refers to the specific detection settings on a microscope or flow cytometer optimized for FITC's green fluorescence.
  • The signal was collected in the FITC channel.

Variants and Related Words

• FITC: The standard and most common abbreviation for fluorescein isothiocyanate.
  • Prepare a solution of FITC in DMSO.
• Fluorescein: The parent compound from which FITC is derived. Fluorescein itself is also a fluorescent dye but lacks the reactive isothiocyanate group for easy conjugation.
• Fluorochrome / Fluorophore: General terms for a fluorescent chemical compound. FITC is a specific type of fluorochrome.

Synonyms

• Fluorescent label: A general term for any fluorescent molecule used for tagging.
• Fluorescent tracer: Emphasizes its use in tracking biological molecules.

Notes on Meaning

• The term specifically refers to the chemical compound itself. Its defining characteristic in science is its dual function: it is both fluorescent and has a chemically reactive group (isothiocyanate) that forms stable bonds with proteins.
• It is almost exclusively used in scientific and medical contexts, particularly in cell biology, immunology, and diagnostic assays.

Noun

1. a fluorochrome commonly conjugated with antibodies for use in indirect immunofluorescence