What is the advantage of using laser light in flow cytometry?

Using laser light in flow cytometry offers several distinct advantages, with higher sensitivity and coherence at specific wavelengths being particularly notable. Lasers provide monochromatic light, meaning they emit light at precise wavelengths. This is crucial in flow cytometry, where the detection of fluorescently labeled cells is based on specific emission spectra. The ability to target these specific wavelengths enhances the clarity of signal detection and separates the different colors of fluorescence emitted by various dyes used in the analysis.

Furthermore, lasers produce light with a high degree of coherence, which enables better focusing of the light into a narrow beam. This focused light allows for a more efficient excitation of fluorescent markers on cells flowing through the cytometer, leading to an increase in the sensitivity of the measurements. Higher sensitivity translates to improved detection of low-abundance markers and a greater ability to resolve closely spaced fluorescent signals, which is essential for accurate analysis in complex biological samples.

In contrast, other light sources like LEDs may not produce the same level of coherence or precise wavelength specificity, potentially resulting in broader emission spectra and reduced sensitivity for some applications. Hence, the choice of laser light fundamentally enhances the overall performance and capability of flow cytometry assays.