What is the primary purpose of lenses in a cytometer?

The primary purpose of lenses in a cytometer is to collect and collimate light from samples. In cytometry, the proper manipulation of light is crucial for accurately measuring and analyzing the properties of cells or particles. Lenses serve to focus the light emitted from fluorescently labeled samples and ensure that it is directed properly toward the photodetectors.

When light passes through a sample, it can scatter or emit fluorescence. Lenses help in collecting this emitted light, guiding it in a way that maximizes the efficiency of detection. By collating the light, lenses help to form clear images and improve the resolution and overall quality of the data obtained from the analysis. This function is critical because the accuracy of measurements in cytometry directly depends on how effectively the light capturing system operates.

The other choices represent different aspects of light manipulation but do not capture the core function of lenses. Reducing light intensity can be important for protecting detectors from saturation but is not the primary role of lenses. Enhancing the wavelength of light is not a function that lenses perform; instead, filters are typically used for wavelength manipulation. Reflecting light towards detectors is a task more associated with mirrors or reflective surfaces rather than lenses, which are primarily concerned with collection and focusing.