February 15, 1935

Prontosil

Animal and clinical results for Prontosil are published

All twelve treated mice lived; all fourteen untreated controls were dead by day four. The compound had looked close to useless in a test tube.

15 February 1935, in a single journal issue

On 15 February 1935, issue 7 of volume 61 of Deutsche Medizinische Wochenschrift published Gerhard Domagk's “Ein Beitrag zur Chemotherapie der bakteriellen Infektionen” at pages 250–253. He reported that Prontosil protected streptococcus-infected mice whether given orally or by injection, even though the compound had shown little useful activity in a test tube.

In the starkest experiment, 26 mice were infected: all 12 treated animals survived, and all 14 untreated controls were dead by day four.

Bedside reports on the following pages

The journal placed clinical reports directly after the experimental paper. Philipp Klee and Herbert Römer reported treatment of streptococcal disease at pages 253–255, and H. T. Schreus reported erysipelas and other infections at 255–256.

Laboratory evidence and physicians' results ran back to back across seven pages.

Why it surfaced when it did

Prontosil had been synthesized in 1932 by Josef Klarer and Fritz Mietzsch, within an industrial azo-dye program at IG Farben's Bayer laboratories that had produced more than 300 azo compounds by that year.

IG Farben kept the work largely inside the company while patenting and clinical investigation proceeded, and its German patent was granted in December 1934. The date marks publication and public clinical introduction — not the first synthesis, the first animal test or the first administration to a patient.

Sources

Researched 23 Aug 2026 8 sources 2 audit passes

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