Rapid measurement of chlorophylls with a microplate reader

This paper describes a robust and rapid procedure for measuring chlorophyll using a microplate reader. The procedure enables direct translation of any published equation developed on a 1-cm pathlength spectrophotometer to any format microplate with any sample volume. Chlorophylls were extracted with methanol because it is compatible with cheap polystyrene plates; however, the principles apply to any solvent system. Keys to obtaining accurate and precise results include determining pathlength in the same solvent used to extract chlorophylls, and avoiding evaporation. After taking these precautions, there was a strong linear 1:1 relationship (R(2) = 0.98-0.99) between microplate and spectrophotometer estimates of chlorophyll concentrations.