FITC
FITC (Ex-Max 490 nm/Em-Max 525 nm)
Fluorescein isothiocyanate (FITC) has an excitation peak at 495 nm and an emission peak at 519 nm. The name FITC is a misnomer in that the isothiocyanate is a reactive form of this dye. Once FITC is conjugated to an antibody, it is simply Fluorescein conjugated. FITC is one of the most widely used dyes for fluorescent applications, therefore most instruments come standard with a 488 nm laser and FITC filter set up. FITC is commonly conjugated to secondary antibodies and used in applications such as flow cytometry, immunocytochemistry, and immunohistochemistry. FITC is relatively dim, sensitive to photobleaching and it is susceptible to changes is pH. There are better performing alternatives to FITC, like Vio®Bright 515, Alexa Fluor™ 488, iFluor® 488, CF®488A and DY-488. FITC is a long-time generic dye with no sole manufacturer or trademark.
Excitation & emission spectra
Key facts
- Excitation maximum
- 490 nm
- Emission maximum
- 525 nm
- Optimal laser line
- 488
- Optimal filter
- 530/43
- Relative brightness
- 2 of 5
- Extinction coefficient
- 73000
- Quantum yield
- 0.5
- Molecular weight
- 389
- Commercial antibodies
- 170.7k from 66 suppliers
FITC has an excitation maximum at 490 nm and an emission maximum at 525 nm, a Stokes shift of 35 nm. Its extinction coefficient is 73000 M⁻¹cm⁻¹. It is optimally excited by the 488 laser line.
Frequently asked questions
- What is FITC?
- Fluorescein isothiocyanate (FITC) has an excitation peak at 495 nm and an emission peak at 519 nm. The name FITC is a misnomer in that the isothiocyanate is a reactive form of this dye. Once FITC is conjugated to an antibody, it is simply Fluorescein conjugated. FITC is one of the most widely used dyes for fluorescent applications, therefore most instruments come standard with a 488 nm laser and FITC filter set up. FITC is commonly conjugated to secondary antibodies and used in applications such as flow cytometry, immunocytochemistry, and immunohistochemistry. FITC is relatively dim, sensitive to photobleaching and it is susceptible to changes is pH. There are better performing alternatives to FITC, like Vio®Bright 515, Alexa Fluor™ 488, iFluor® 488, CF®488A and DY-488. FITC is a long-time generic dye with no sole manufacturer or trademark.
- What laser excites FITC?
- FITC is optimally excited by the 488 laser line. Its excitation maximum is 490 nm.
- What filter should I use to detect FITC?
- A 530/43 filter captures the peak of the FITC emission near 525 nm with minimal spillover.
- How bright is FITC?
- FITC has a relative brightness of 2 out of 5 (quantum yield 0.5).
- How many antibodies are available conjugated to FITC?
- FluoroFinder tracks 170709 commercially available FITC conjugates, searchable by target, clone, host and application.