Cuvettes are small narrow circular, triangular, square, or rectangular sample containers for spectroscopy. They are sometimes called cells. Cuvettes are filled with samples, usually diluted or suspended in liquid, and placed within a spectroscopy device, such as a colorimeter, electroporator, fluorometer, spectrometers, spectrophotometer, or tintometer.
This video discusses a spectrophotometer, including placement of the cuvette.
Video credit: Worcester Polytechnic Institute
Cuvettes vary widely, depending on their use and the measuring instrument. Certain uses require shaped, tinted, self-masking, flow, or water-jacketed cells. Electropolation cuvettes are fitted with electrodes. Tandem (divided) cuvettes have two chambers. Demountable cells can be taken apart after each use.
Common retangular cuvettes have a 10 mm path length, but they can range from as little as 1 mm to 100 mm and more. Volume varies by the cuvette's size and the thickness of its walls. Standard, semi-micro, micro, and even smaller reservoir cuvettes are available. Glass, plastic, and quartz are common cuvette materials. Special treatment is necessary for cryogenic uses.
Certain cuvettes have roughened walls on opposite sides to improve grip and handling; the perpendicular walls are clear for measuring. Single- or limited-use applications can benefit from disposable or semi-disposable cuvettes. Stopper, screw, or septum tops may be colored or frosted for identification and labeling.