please help..about optical density on biomass concentration?

Question

Disccuss the advantages and disadvantages of optical density as method of determination of biomass concentration

Answer 1

Optical density is a method of measuring concentrations in solution. It depends on the concentration of material, and on how strongly it absorbs light of the wavelength that you are using to make the measurement. It works very badly with suspensions that scatter light.

So if you are using it to measure biomass, it will only work for a form of biomass that is soluble and where you know how strongly the material absorbs the light that you are using. It will not work for insoluble materials, nor for mixtures of unknown composition since you do not know how strongly they absorb the relevant light.

Actually, I am very puzzled by why this question is being asked. Usually when people talk about biomass, they are talking about solid plant material such as wood or straw, mainly cellulose. So I wonder why anyone is ever puzzling about the concentration of biomass, since concentration must refer to a solution.