Original paper

Determination of algal cell culture (Desmodesmus subspicatus) concentration using a microplate reader

Kočí, Vladimír; Dragoun, Darek; Lukavský, Jaromír


The reliable determination of the algal cell concentration is a crucial point in toxicological algal bioassays; which belong to the standardized battery of toxicity tests. Using cultures of the green microalga Desmodesmus subspicatus in microplates, we recommend the following protocol: a) a wavelength of 682 nm and/or 750 nm, for reading of algal cell concentration; b) agitation during cultivation, if necessary, to increase the sensitivity and data quality of the bioassay; c) approximately 10 seconds of shaking before OD evaluation; d) waiting a 30 minute interval, after the termination of shaking, should be used, to achieve a stable value of optical density; e) minimum duration of the bioassay to 96 hours; g) the response, reading algal cell numbers in suspension, is maximized when 9 beams (3×3) are used to read the optical density.


algal bioassaymicroplate spectrophotometrycell concentrationtoxicity testing