THE USE OF MINIATURIZED ALGAL BIOASSAYS IN COMPARISON TO THE STANDARDFLASK ASSAY

Plastic test tubes and microplates were used in two miniaturized algal bioassays for comparison with a standard algal operational procedure in glass flasks. All three methods used spectrophotometrical measureme nts of growth of the green alga Raphidocelis subcapitata after 72 h. T he EC50 values were determined from growth inhibition results for thre e metal compounds (CuSO4. 5H(2)O, ZnSO4. 7H(2)O, KMnO4), one pesticide (trichlorphone), and eight pharmacological drugs (oxytetracycline hyd rochloridum, peroxysulphate, toltrazuril, pyrrolidone, formaldehyde, s odium chloride, chloridochlornane, and benzensulphochloramidum). Good interprocedural concordance for chemicals were reported and the compar ability of toxicity results was demonstrated also for the eight enviro nmental samples. This comparative study describes and recommends two a lgal microbioassays that can be used as an alternative to the standard flask toxicity test with algae. (C) 1998 by John Wiley & Sons, Inc. E nviron Toxicol Water Qual 13: 235-241, 1998.