Answer:
He brings to focus the research and the use of chemical substances against infections.
Explanation:
Paul Ehrlich was born in Strehlen, Prussia, on March 14, 1854, in an influential Jewish family. As a medical student at the University of Leipzig, he conducted several researches on the presence of foreign substances in the body and on dyestuffs and their application in the study of different toxic processes. From 1889 onwards, he concentrated on research on immunological processes and on the study of some toxins, such as diphtheria, which led to the establishment of the theory of antibodies developed by the organism in reaction against microbial disorders. Subsequently, it analyzed the action and efficacy of several therapeutic agents and chemicals and proved its lethal effect on some pathogenic protozoa.
His studies on cell and tissue staining processes and their classification of chemical dyes into acids, both basic and neutral, revolutionized laboratory methods and opened new horizons for the treatment of infectious diseases. In the field of chemotherapy, after conducting hundreds of experiments with highly toxic chemical compounds, in 1909 he managed to transform arsenous anhydride into organic derivatives and obtain a new preparation, Salvarsan, which became the main medication against syphilis, until the appearance of penicillin and new antibiotics.
