HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Ando, K. Articles by Nishimura, H. Search for Related Content PubMed Articles by Ando, K. Articles by Nishimura, H.

On the Heat Stability of the Diphtheria Toxin

From the Bacteriological Department (K. Ando), Hygienic Institute (Director, S. Kanai) of the S. M. R. Co., Dairen, So. Manchuria

Abstract

The property of heat sensitiveness is considered as a characteristic of bacterial exotoxins. In a previous paper (2), however, we have pointed out that a part of the scarlatinal toxin could stand boiling for thirty minutes. It seems rather curious that the scarlatinal toxin is an exception to this general rule. In order to analyse this general rule—heat sensitiveness of exotoxins—we examined carefully the heat stability of the diphtheria toxin as a typical exotoxin and found that a part of the diphtheria toxin also could stand boiling for thirty minutes.

Five portions of diphtheria toxin No. 166 (pH 8.5; M.L.D. = 1/300 cc.) heated to varying temperatures (60°, 70°, 80°, 90°, and 100°C.) for thirty minutes were tested for their M.R.D. on two guinea pigs and it was found that the ratio of M.R.D. of the heated toxins and that of unheated control was 50 (60°C.), 500 (70°C.), 2,000 (80°C.), 10,000 (90°C.) and 10,000 (100°C.) respectively.