Nephlometry is a technology based on the principle of scattering of light. When a particle comes on the path of light rays, the rays bang with it and change their direction of movement. This phenomenon is called scattering. Size, concentration and shape of the molecules altogether determines the amount of scattered light. Size and shape determines the angle of scatter and concentration intensifies the scattered at that particular angle. Generally molecules would vary either by size or by shape or by both. Hence, they will become unique from these aspects. Amount of light scattered will also be determined by the wavelength of the incident light.

If the scattered light at any particular angle is measured, one can confidently say that the scattering is due to a particular molecule. This forms the base for "NEPHELOMETRY". In nephlometry, the scatter caused by the molecules is measured mostly at 90º angle. The liquid sample is exposed to the beam of light rays in a transparent holder. The rays get scattered and a detector kept at right angle of the light path detects the intensity of rays at that angle.

This of course is made quantifying and thereby more precise by rehearsing the phenomena with a known molecule at known concentration. The data obtained while this STANDARD RUN is used as a master reference for a known molecule at unknown concentration. Hence, nephlometry is a quantitative method and on the basis of the scattering by known concentrations, an unknown concentration may be derived. The concept of nephlometry is mostly applied for estimations of proteins as the latest breakthrough.

Superiority of Nephlometry:
- Nephlometric methods are more sensitive with a detection limit of approximately 10mg/mL than turbidometric methods which has the detection limit of 20 to 30mg/mL.
- Nephelometry is fast with kinetic method. Results are obtained within minutes.
- Thus, sensitivity, precision, accuracy and high turrnaround time make nephelometry a preferred choice for the laboratory estimation of special proteins.