who developed a useful staining method to identify bacteria
Hans Christian Gram
title: Bacteria text: bacteria based on their morphology. Though it was known in the nineteenth century that bacteria are the cause of many diseases, no effective antibacterial treatments were available. In 1910, Paul Ehrlich developed the first antibiotic, by changing dyes that selectively stained "Treponema pallidum"—the spirochaete that causes syphilis—into compounds that selectively killed the pathogen. Ehrlich had been awarded a 1908 Nobel Prize for his work on immunology, and pioneered the use of stains to detect and identify bacteria, with his work being the basis of the Gram stain and the Ziehl–Neelsen stain. A major step forward in the study of bacteria title: Hans Christian Gram text: he developed a method for distinguishing between two major classes of bacteria. This technique, the Gram stain, continues to be a standard procedure in medical microbiology. In 1891, Gram taught pharmacology, and later that year was appointed professor at the University of Copenhagen. In 1900, he resigned his chair in pharmacology to become professor of medicine. The work that gained Gram an international reputation was his development of a method of staining bacteria, to make them more visible under a microscope. The stain later played a major role in classifying bacteria. Gram was a modest man, and in his initial title: Gram stain text: can be definitively classified by this technique. This gives rise to "gram-variable" and "gram-indeterminate" groups. The method is named after its inventor, the Danish scientist Hans Christian Gram (1853–1938), who developed the technique while working with Carl Friedländer in the morgue of the city hospital in Berlin in 1884. Gram devised his technique not for the purpose of distinguishing one type of bacterium from another but to make bacteria more visible in stained sections of lung tissue. He published his method in 1884, and included in his short report the observation that the typhus bacillus did not retain the stain. title: Romanowsky stain text: Romanowsky stain Romanowsky staining is a prototypical staining technique that was the forerunner of several distinct but similar methods, including Giemsa, Jenner, Wright, Field, May Grunwald stain and Leishman stains, which are used to differentiate cells in pathologic specimens. It was named after the Russian physician Dmitri Leonidovich Romanowsky (1861–1921), who invented it in 1891. Paul Ehrlich had used mixtures of acidic and basic dyes for this purpose in 1879: e.g. fuchsine (acid dye) and methylene blue (basic dye). In 1891, Romanowsky developed techniques using a mixture of eosin Y and modified methylene blue that produced a surprising hue unattributable title: Paul Ehrlich text: Paul Ehrlich Paul Ehrlich (; 14 March 1854 – 20 August 1915) was a Nobel prize-winning German-Jewish physician and scientist who worked in the fields of hematology, immunology, and antimicrobial chemotherapy. He is credited with finding a cure for syphilis in 1909. He invented the precursor technique to Gram staining bacteria. The methods he developed for staining tissue made it possible to distinguish between different types of blood cells, which led to the capability to diagnose numerous blood diseases. His laboratory discovered arsphenamine (Salvarsan), the first effective medicinal treatment for syphilis, thereby initiating and also naming the concept of chemotherapy.