Fluorescence is a process distinct from incandescence (i. e. emission of light due to high temperatures). Heating is generally detrimental to the process of fluorescence, and most substances, when fluorescing, produce very little heat. For this reason fluorescence has commonly been referred to as "cold light".

In the standard conceptual model of molecules the electrons occupy distinct orbits and thus energy levels. This is a simple view of molecules, but it does serve to outline the general process of fluorescence. A common result of directing light on a molecule that absorbs rather than transmits is that one or more of the electrons of the molecule are "kicked" into a higher energy state. All these excited electronic states are unstable, and sooner or later the electrons will loose their excess energy and fall back to lower energy states. This excess energy can be dissipated in several ways, the most common being simply to increase atomic vibrations within the molecule. But some molecules are capable of emitting some of the energy as light. This is what we see as fluorescence.

Biochemists and physicists have exploited these light-emitting fluorophores as labels in a large number of laboratory and clinical tests. BERTHOLD TECHNOLOGIES has developed new instruments for this growing market. Also here the understanding of BERTHOLD TECHNOLOGIES is to improve sensitivity leading to instruments which can

detect and identify

better and better. Today’s new generation of instruments are using luminescence and fluorescence for detection simultaneously and combining them. The sensitivity of such multimode readers is even better than that of former dedicated instruments enabling, e. g. BRET or FRET applications.