When measuring light scattering it is important to consider the wavelength of light used a bacterial culture. Microorganisms may contain numerous macromolecules that will absorb light, including DNA (254 nm), proteins (280 nm), cytochromes (400-500 nm), and possible cell pigments. When measuring bacteria by light scattering it is best to pick a wavelength where absorption is at a minimum and for most bacterial cultures wavelengths around 600 nm are a good choice. However, the exact wavelength chosen is species specific. It is best to pick a wavelength where absorption is at a minimum.