What is the purpose of optical filters in flow cytometry?

The purpose of optical filters in flow cytometry is to allow specific wavelengths of light to pass while blocking others. This functionality is essential for the detection of fluorescently labeled particles, such as cells, in a fluid sample. Each fluorescent marker emits light at a particular wavelength when excited by a laser, and filters are used to isolate that fluorescence from background light and other excitation signals.

By selectively allowing only certain wavelengths to be detected, optical filters enhance the sensitivity and specificity of the measurements. This capability is crucial in flow cytometry, where multiple fluorescent markers are often used to characterize different cell populations simultaneously. Utilizing specific filters corresponding to the emission spectra of the different fluorophores ensures that the signals from those labels can be accurately measured and differentiated, leading to precise analysis of the sample being examined.