The effect of formalin and Lugol’s iodine solution on protozoal cell volume

350 210 Stroud Water Research Center

Zinabu, G.M., and T.L. Bott. 2000. Limnologica 30:59–63.

doi: 10.1016/S0075-9511(00)80044-4


The effects of formalin, Lugol’s iodine solution and a mixture of these preservatives on the cell volumes of two protozoan species (the flagellate Chilomonas sp. and the ciliate Cyclidium sp.) were studied using phase contrast microscopy. While the percent of live volume was affected by the preservative used and protozoan type, storage time was of overriding importance. Within 10 min., cells exposed to formalin and formalin + Lugol’s solution increased in biovolume, but by 24 h cell shrinkage was in the range of 6 – 19% of live biovolume, formalin fixed samples having the least amount of shrinkage. After one month of storage, cell biovolume was reduced to between 60 and 65% of live biovolume in all three preservatives.


NSF Award No. DEB-0096276. Title: LTREB: Stream ecosystem structure and function within a maturing deciduous forest. Duration: August 1998–July 2003.