Effects of Vital Dyes on Early Development of the Amphibian Embryo

Abstract

Summary

1. Eggs of Rana pipiens were exposed to solutions of the vital dyes Xile Blue Sulfate, Neutral Red and Bismark Brown under different conditions. Concentrations less than the following allowed normal development of eggs and embryos: Nile Blue Sulfate 1 :750,000; Seutral Red 1 :250,-000; Bismark Brown 1:100,000.

2. Developmental abnormalities appeared with use of stronger concentrations than listed above.

3. Early cleavage was unaffected by otherwise toxic concentrations even to 1:10,000. Gastrulation proved to be the critical point in development when toxic effects of the dyes began to produce abnormalities.

4. Short exposure to toxic concentrations, even during unaffected cleavage, resulted in abnormalities appearing at subsequent stages of development.

5. Developmental stages 9 and 10 were more susceptible to toxic effects than were stages 2, 6, 11, 12, 14 using Nile Blue Sulfate of 1:100,000 and 1:150,000 concentrations.

6. The pH of the medium mas shown to influfnce the toxicity effects.

7. When Nile Blue Sulfate, Seutral Red and Bismark Brown are used as vital dyes, the factors of concentration, length of exposure stage must considered to avoid induced abnormalities in development, most of which begin at the time of gastrulation.