Which light source is most commonly used in modern flow cytometry instruments?

In modern flow cytometry, lasers are the predominant light source used, and there are several reasons for this. Lasers provide a highly focused and intense beam of light, which is essential for accurately exciting fluorescent dyes used in labeling cells. The monochromatic nature of laser light ensures that specific wavelengths can be utilized for different fluorescent markers, allowing for precise measurements of multiple parameters simultaneously.

Lasers also have the capability to produce a more stable and coherent light source than other options listed. This stability is crucial for the reproducibility of results, as variations in light intensity can affect the sensitivity and accuracy of cytometric measurements. The ability to selectively filter the light wavelength also enhances the resolution of detection, making lasers ideal for distinguishing between closely spaced fluorescent emissions.

The other light sources, such as arc lamps and incandescent bulbs, while they can produce a broad spectrum of light, do not provide the same level of coherence or intensity and can introduce noise in the data. LEDs, although they are becoming more common in newer flow cytometry systems due to advances in their design and output, have not yet reached the level of adoption or versatility that lasers offer, especially in applications requiring highly detailed and accurate multiparametric analysis.

Therefore, the widespread use of lasers in modern flow cyt