An evaluation of three conventional histological techniques for staining the cerata of Cratena pilata

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Fixation and staining methods for different types of tissue in the marine nudibranch Cratena pilata were evaluated. Cratena pilata, a marine snail in the Phylum Mollusca, has the ability to take stinging cells, called nematocysts, from ingested animals belonging to another phylum, the coelenterates, and use them for their own defense. A total of 10 nudibranchs were used; 6 were preserved in 10% formalin and 4 in Helly's fixative. Three different types of stains were compared: Hematoxylin and eosin (H&E), Cason's modified trichrome stain, and Bielschowsky's silver stain. The animals fixed in Helly's fixative were stained with Cason's modified trichrome stain and H&E. The formalin fixed animals were stained with either Cason's modified trichrome stain or Bielschowsky's silver stain. Helly's fixative in conjunction with H&E proved to be the best combination to examine the general morphology of Cratena pilata. Cason's modified trichrome stain was the best stain for differentiating gut tissue, muscle, basement membrane, nematocysts, and the cerebral ganglion. Although Bielschowsky's silver stain stained nerves, Cason's modified trichrome stain proved to be the better stain to differentiate neuronal axons and cell bodies.

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Journal of Histotechnology