Paul Ehrlich in the context of "Basophil granulocyte"

Stanislaus Josef Mathias von Prowazek, Edler von Lanow (12 November 1875 Jindřichův Hradec, Bohemia – 17 February 1915, Cottbus), born Stanislav Provázek, was a Czech biologist, zoologist and parasitologist, who along with pathologist Henrique da Rocha Lima (1879-1956) discovered the pathogen of epidemic typhus.

As a student in biology at the University of Prague, he was influenced by the teachings of zoologist Berthold Hatschek and philosopher Ernst Mach. Other important influences to his career were immunologist Paul Ehrlich at the Institute for Experimental Therapy (later named Paul Ehrlich Institute) in Frankfurt (1901) and zoologist Richard von Hertwig at the University of Munich.

A mast cell (also known as a mastocyte or a labrocyte) is a resident cell of connective tissue that contains many granules rich in histamine and heparin. Specifically, it is a type of granulocyte derived from the myeloid stem cell that is a part of the immune and neuroimmune systems. Mast cells were discovered by Friedrich von Recklinghausen and later rediscovered by Paul Ehrlich in 1877. Although best known for their role in allergy and anaphylaxis, mast cells play an important protective role as well, being intimately involved in wound healing, angiogenesis, immune tolerance, defense against pathogens, and vascular permeability in brain tumors.

The mast cell is very similar in both appearance and function to the basophil, a type of white blood cell. Although mast cells were once thought to be tissue-resident basophils, it has been shown that the two cells develop from different hematopoietic lineages and thus cannot be the same cells.

Basophils are a type of white blood cell. Basophils are the least common type of granulocyte, representing about 0.5% to 1% of circulating white blood cells. They are the largest type of granulocyte. They are responsible for inflammatory reactions during immune response, as well as in the formation of acute and chronic allergic diseases, including anaphylaxis, asthma, atopic dermatitis and hay fever. They also produce compounds that coordinate immune responses, including histamine and serotonin that induce inflammation, and heparin that prevents blood clotting, although there are less than that found in mast cell granules. Mast cells were once thought to be basophils that migrated from the blood into their resident tissues (connective tissue), but they are now known to be different types of cells.

Basophils were discovered in 1879 by German physician Paul Ehrlich, who one year earlier had found a cell type present in tissues that he termed mastzellen (now mast cells). Ehrlich received the 1908 Nobel Prize in Physiology or Medicine for his discoveries.

The Ziehl–Neelsen stain, also known as the acid-fast stain, is a bacteriological staining technique used in cytopathology and microbiology to identify acid-fast bacteria under microscopy, particularly members of the Mycobacterium genus. This staining method was initially introduced by Paul Ehrlich (1854–1915) and subsequently modified by the German bacteriologists Franz Ziehl (1859–1926) and Friedrich Neelsen (1854–1898) during the late 19th century.

The acid-fast staining method, in conjunction with auramine phenol staining, serves as the standard diagnostic tool and is widely accessible for rapidly diagnosing tuberculosis (caused by Mycobacterium tuberculosis) and other diseases caused by atypical mycobacteria, such as leprosy (caused by Mycobacterium leprae) and Mycobacterium avium-intracellulare infection (caused by Mycobacterium avium complex) in samples like sputum, gastric washing fluid, and bronchoalveolar lavage fluid. These acid-fast bacteria possess a waxy lipid-rich outer layer that contains high concentrations of mycolic acid, rendering them resistant to conventional staining techniques like the Gram stain.

Ilya Ilyich Mechnikov (15 May [O.S. 3 May] 1845 – 15 July 1916), gallicised and known in Western sources as Élie Metchnikoff, was a zoologist from the Russian Empire of Moldavian noble ancestry best known for his research in immunology (study of immune systems) and thanatology (study of death). He and Paul Ehrlich were jointly awarded the 1908 Nobel Prize in Physiology or Medicine "in recognition of their work on immunity".

Mechnikov was born in a region of the Russian Empire that is today part of modern-day Ukraine to a Moldavian noble father and a Ukrainian-Jewish mother. He later moved to France. Given this complex heritage, five different nations and peoples lay claim to Metchnikoff. Despite having a mother of Jewish origin, he was baptized Russian Orthodox, although he later became an atheist.