Biological Assay of the Toxin From Shellfish

Abstract

A conventional quantal response assay procedure was employed to determine the LD50 of shellfish extracts. The slope of the log dose – response line obtained with butter clam extracts was not significantly different from that found with scallop liver extracts. When kept in a dry, cold state, a lyophilized extract of scallop liver was stable throughout a test period of nearly three years. Such a preparation could be used as a reference standard for the bio-assay of shellfish toxin. Female mice were more susceptible to the paralytic poison than male mice. The LD50 per mouse was related directly to the average body weight of the test animals. The volume of the injection medium had no effect on either the magnitude of the LD50 or the slope of the probit regression line. A highly significant inverse relationship was demonstrated between the toxicity measured in mouse units, a procedure based on the mean death time of the test animals, and the LD50 per kgm. of mouse determined by an assay with an all-or-none response.

The toxin fromGymnodinium veneficumBallantine

“…Stephenson of the Department of National Health and Welfare of Canada (see also Stephenson et al, 1955). This was also administered to mice during the series of tests.…”

Biochemical Studies on Paralytic Shellfish Poisons

“…Medcof el al.I7 have described a similar assay for the poison in shellfish and Stephenson et a1. 18 have studied the conditions for the assay in detail.…”

Toxic Marine Flagellates; their Occurrence and Physiological Effects on Animals

“…In view of the human problems involved the emphasis has been on the medical and preventive aspects. Extracts from the digestive glands of the poisoned mussels have been prepared and injected into mice, and by this means a bioassay technique has been developed (Stephenson, Edwards, MacDonald & Pugsley, 1955). The poison has also been extracted from phytoplankton and the connexion between the two established (Sommer, Whedon, Kofoid & Stohler, 1937;Riegel, Stanger, Wikholm, Mold & Sommer, 1949).…”