logo
AAT Bioquest

What is the difference between prisms and diffraction gratings in terms of light dispersion when they are used in spectral flow cytometry?

Posted June 22, 2020


Answer

Prisms and gratings are the two most common types of dispersive optics. The major difference between these two elements is that the dispersion of prisms is non-linear while gratings offer linear dispersion.

  • The dispersion of prisms is efficient over a wide range of wavelengths and the throughput of a prism is usually pretty high (>90%). However, they refract light in a wavelength-dependent manner, resulting in the non-linear dispersion and accordingly the wavelength-dependent resolution. Therefore, proper correction of the non-linear dispersion through a mathematical algorithm is required when prisms are used on a spectral flow cytometer.
  • Diffraction gratings, on the other hand, can spread light linearly or equally into the chosen detector, which can improve resolution when used at their intended wavelength and may allow for easier implementation into some systems.
Additional resources

Fundamentals of Flow Cytometry

Cell Meter™ FITC-Annexin V Binding Apoptosis Assay Kit *Optimized for Flow Cytometry*

Picot, J., Guerin, C. L., Le Van Kim, C., & Boulanger, C. M. (2012). Flow cytometry: retrospective, fundamentals and recent instrumentation. Cytotechnology, 64(2), 109-130.

Nolan, J. P., & Condello, D. (2013). Spectral flow cytometry. Current protocols in cytometry, 63(1), 1-27.