Biochemical Techniques and Instrumentation

1.2.5. Sample cell

Sample dissolved in suitable solutions is taken in an optically transparent sample cell called cuvette. Borosilicate glass and normal plastics cuvettes are used in the visible range of spectrum ( upto 350 nm) as they absorb UV light. Quartz or silica cuvettes are used for UV range of spectrum and are transparent to wavelength above 180 nm. A control or reference cuvette should be optically identical to the test cuvette. The optical path length of the cuvette is mostly 1 cm. Cuvettes with path length of 100, 20, 5, 2 and 1 mm are also available for particular applications. Disposable plastic cuvettes are now available that allow measurements over the entire range of the UV/Vis spectrum.