Fluorescence Intensity

Fluorescence intensity detection has a much broader range of applications than absorbance detection. For fluorescence intensity measurements, an optical system (the excitation system) illuminates the sample using a specific wavelength. The excitation wavelength is selected by an optical filter or a monochromator, thereby exciting the sample. The excitation causes the sample to emit light (i.e. fluoresce) at a different wavelength. The emitted light is collected by a second optical system (the emission system) and the signal is measured by a light detector such as a photomultiplier tube (PMT).

Samples are chemically bound with fluorescent tag

Samples are chemically bound with fluorescent tag

Light at a specific wavelength excites the sample

Figure 1. Samples are chemically bound with fluorescent tag

Excited samples emit light at a different wavelength

Figure 2. Light at a specific wavelength excites the sample.

The advantages of fluorescence detection over absorbance detection are increased sensitivity and a broader application range, given the wide selection of fluorescent labels available today. For example, a technique known as calcium imaging measures fluorescence intensity of calcium-sensitive dyes to assess intracellular calcium levels.

Fluorescence Intensity is available in:

 
link