In electrophoresis scatter, which pattern is associated with large particles?

• A. Mie scatter (Forward)
• B. Rayleigh scatter
• C. Bragg scatter
• D. Raman scatter

Answer: (A)

The main idea is how particle size relative to the light wavelength changes the scattering pattern. For large particles, scattering is described by Mie theory, which produces a strong forward-directed pattern. When particles are comparable to or larger than the light’s wavelength, the scattered light concentrates in the forward direction, giving a pronounced forward peak. In contrast, Rayleigh scattering applies to particles much smaller than the wavelength and tends to be more isotropic with weaker forward emphasis. Bragg scattering comes from diffraction by a regular crystal lattice, not from particle size in a dispersed sample, and Raman scattering is inelastic scattering used to probe molecular vibrations, not a size-related directional pattern. So the pattern associated with large particles is Mie scatter (Forward).