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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Ref ID : 4037

Donald M. Spoon, Charles O. Feise II, and Rebecca Sue Youn; Poly(Ethylene Oxide), a New Slowing Agent for Protozoa. J.Protozool. 24(3):471-474, 1977

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The water-soluble, viscoelastic resin Polyox (WSR 301), a poly(ethylene oxide) of high molecular weight (~4 million) is introduced as a new slowing agent for protozoa. Generally, as the kinetic viscosity of the resin increased from 0.25% to 1% (w/v), the swimming velocity of Euglena gracilis, Didinium nasutum, Paramecium aurelia, Blepharisma undulans, and Prorodon platyodon decreased. The 1.0% solution had the highest viscosity and decreased velocity more effectively than 1.0% methyl cellulose and Protoslo solutions. The Polyox solutions differed from those of methyl cellulose and Protoslo by having, in addition to viscous drag, an elastic recoil that pulled the protozoa backwards when their swimming efforts stopped. The toxicity of these slowing agents was determined using 10 P. aurelia/test slide preparation. Paramecium numbers decreased in 1.0% methyl cellulose and Protoslo to nearly zero by 24 hr; in Polyox, not only were most of these ciliates alive after 24 hr, but many survival for 96 hr and divisions occurred in 0.25% and 0.50% solutions.