Essay On Fluorescence

1. Microscopy

The discipline of science which involves magnifying objects which cannot be seen with the naked eye is known as microscopy.

2. Fluorescence- an introduction

Certain substances, when irradiated with light (UV, blue or green) emit radiations of their own, whose wavelength is longer than that of the exiting light. This process is called luminescence.

There are two types of luminescence:

If the excited radiation persists only so long as the exciting light acts on the sample then it is called fluorescence. Figure 1: Fluorescence

If the exciting light is switched off the secondary emission persists for some time at appreciable intensity then we name it as phosphorescence. Figure 2: Phosphorescence 2.1. Primary fluorescence

Some specimens have the property of emitting fluorescent light in unstained forms i.e when no stains are

Microspectography

Microspectography is a technique highly specialized for the measurement of spectra. Fluorescing dyes sometimes show a different spectral behavior in the unbound state found in solution in cuvettes, and the bound state to cellular components. Spectral characteristics are determined by combining a fluorescence microscope with a spectrofluorometer. This instrument detects the variance of the adsorption wavelength and the variance of the emission wavelength

4.4. Quantitative fluorescence microscopy

Quantitative fluorescence microscopy involves taking measurements from fluorescing specimens. The basic measuring technique is called microfluorometry. This procedure involves measuring the brightness of fluorescence emission from a defined area of the specimen under standardized conditions. This technique is most commonly applied to determining the amount of some specific substance such as DNA. The fluorescent intensity of the specific substance is compared to that of the standard. The standard contains a known amount of the