Studies on the permeability of living cells. XV. A review of the penetration into Valonia ventricosa of oxidation-reduction indicators including m-bromo phenol indophenol and guaiacol indophenol
✍ Scribed by Brooks, Matilda Moldenhauer
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1933
- Tongue
- English
- Weight
- 631 KB
- Volume
- 3
- Category
- Article
- ISSN
- 0095-9898
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✦ Synopsis
This investigation is a continuation of the study of the penetration of various oxidation-reduction indicators into sap of Valonia ventricosa. It deals with two indophenol dyes not heretofore used, namely, guaiacol indophenol and meta-bromo phenol indophenol. These dyes are of the same lot made by Dr. W. Mansfield Clark, to whom the writer is indebted for their presentation. They are of special interest because of their position on the E,-pH scale as devised by Clark ('28).
Guaiacol indophenol is the most negative of the indophenol dyes which have so far been found to penetrate Valonia. It is in the region near redox neutrality, between Lauth's violet, which penetrates in the oxidized form, and o-cresol iiidophenol, which penetrates in the reduced form (Brooks, '30, '32 a).
The second dye is in the most positive region of the series of indicators as devised by Clark. The method of experimentation was substantially that described in previous publications (Brooks, '26). The marine alga Valonia ventricosa was used. The plants were placed for various periods of time in solutions of the dye dissolved in sea water, taken out at intervals, carefully rinsed off with distilled water, and dried off with filter paper, to take off all the moisture and any dye adhering to the surface of the cell.