Which item is NOT listed as an important component of a fluorometer?

• A. Gas discharge lamp (UV) – Mercury
• B. 2 Monochromators/Filters
• C. Photomultiplier tube
• D. Glass cuvette with sample

Answer: (D)

The item being tested is not an internal part of the fluorometer. A fluorometer works by using an excitation source to illuminate the sample, optics (monochromators or filters) to select the excitation and emission wavelengths, and a sensitive detector to measure the emitted light. The gas-discharge UV lamp provides the excitation photons, the dual monochromators/filters shape and separate the excitation and emission light, and the photomultiplier tube converts the emitted photons into an electrical signal. The glass cuvette with the sample, while essential for holding the sample in the path of light, is a consumable accessory and not a built-in component of the instrument itself. It’s chosen (often quartz rather than glass) for its optical transparency at the wavelengths of interest, but as a part of the setup it’s not considered an intrinsic fluorometer component.