Multi-Angle Light Scattering Detection (MALS) results in the measurement of absolute molecular weight which is independent from the column calibration. The amount of light scattered (measured by MALS) is proportional to the molar mass of the polymer (M), the concentration (c) of the polymer, and the square of specific refractive index increment (dn/dc). Special procedures must be taken if the sample absorbs or if the sample fluoresces with exicitation at the wavelength of the laser (663.1 nm).