This article is about a kind of glassware. For the region of the Republic of the Congo, see Cuvette Region.
A disposable, plastic cuvette.
A cuvette is a small tube of circular or square cross section, sealed at one end, made of plastic, glass, or fused quartz (for UV light) and designed to hold samples for spectroscopic experiments. Disposable plastic cuvettes are often used in fast spectroscopic assays, where speed is more important than high accuracy. Glass cuvettes are typically for use in the wavelength range of visible light and fused quartz tends to be used in the UV through NIR ranges.
Some cuvettes will be clear only on opposite sides, so that they pass a single beam of light through that pair of sides; often the unclear sides have ridges or are rough to allow easy handling. Cuvettes to be used in fluorescence spectroscopy must be clear on all four sides because fluorescence is measured at a right-angle to the beam path to limit contributions from beam itself. Some cuvettes, known as tandem cuvettes, have a glass barrier that extends 2/3 up inside, so that measurements can be taken with two solutions separated, and again when they are mixed. Typically, cuvettes are 10 mm (0.39 in) across, to allow for easy calculations of coefficients of absorption.
Cuvettes to be used in circular dichroism experiments should never be mechanically stressed, as the stress will induce birefringence in the quartz and affect the measurements made.
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