Table of Contents
Introduction to Nephelometry
Nephelometry is a technique used to measure the amount of light scattered by particles in a sample. The amount of light scattered is proportional to the size of the particles in the sample.
Principle of Nephelometry
Nephelometry a technique used to measure the amount of light scattered by particles in suspension. The scattered light then collected by a detector and its intensity measured. The intensity of the light is inversely proportional to the size of the particles.
Scatter and the Concentration of Particles
- In a gas or liquid, particles (molecules or atoms) are constantly in motion. This motion is random, meaning that the direction and speed of a particle is always Changing.
- When a gas or liquid spread out evenly, the concentration of particles is the same everywhere. This is called a uniform concentration.
- When a gas or liquid concentrated in one place, the concentration of particles is higher in that place than in other places. This called a non-uniform concentration.
The Wavelength of the Light Source
The wavelength of a light source is the distance between two consecutive peaks in a wave. It usually measured in nanometers (nm).
Nephelometry Instrumentation: How it Detected?
Nephelometers detect light scatter from suspended particles in a liquid. The light scatter is directly proportional to the number of particles in the liquid.
Nephelometry Uses
Nephelometry used to measure the concentration of suspended particulate matter in a sample of water.
Microplate-Based Nephelometry
This technique used to determine the concentration of a protein in a solution. A protein solution mixed with a fluorescently labeled antibody specific for the protein. This mixture then added to a plate that has been coated with the antibody. The plate then incubated and washed. The amount of fluorescent label on the plate is proportional to the amount of protein in the original solution.
Drug Solubility Assays
- The solubility of a drug is its ability to dissolve in a solvent. The higher the solubility of a drug, the more easily it will dissolve in a solvent. There several methods that can used to measure the solubility of a drug.
- One common method is to measure the amount of time it takes for a drug to dissolve in a solvent. This often done using a stirring device, which slowly rotated in a container of solvent. The time it takes for the drug to dissolve then recorded.
- Another common method is to measure the amount of drug that dissolved in a given amount of solvent. This can done using a graduated cylinder or a pipette. The amount of drug that dissolved can then compared to the amount of drug that added to the solvent.
