- Person
- Paul Ehrlich
- Lived
- 1854–1915
- Field
- Immunology & chemotherapy
- From
- German
The story
As a medical student in the 1870s, Paul Ehrlich was fascinated by the brilliant aniline dyes then pouring out of Germany's chemical industry. His cousin Karl Weigert had pioneered their use for studying tissues, and Ehrlich spent hours testing how they coloured different cells. In 1878 he earned his doctorate at Leipzig with a dissertation on the theory and practice of staining animal tissues.
That year he became an assistant to Professor Theodor Frerichs at the Charité hospital in Berlin, who gave him every opportunity to continue the work. Ehrlich showed that the dyes could be grouped as basic, acid or neutral, and he created new neutral dyes of his own. He also devised a simple way to prepare blood: a drop placed between two glass slides and heated over a Bunsen burner fixed the cells while still allowing them to be stained.
With these tools he could, for the first time, tell the various white blood cells apart by how their granules took up the different dyes. He distinguished the non-granular lymphocytes, mono- and polynuclear leucocytes, eosinophil granulocytes and mast cells. From 1880 he turned to red blood cells as well, showing the existence of nucleated red cells and identifying the precursors from which mature red cells develop.
This work gave doctors the basis for analysing anaemias and for classifying leukaemias. His duties at the Charité included testing patients' blood and urine, and in 1881 he published a urine test that helped distinguish typhoid from simple diarrhoea, using a solution still known as Ehrlich's reagent. Because he combined chemistry, biology and medicine in a new way, many doctors who lacked chemical training rejected his work at first, and no suitable professorship came his way.
In time his methods prevailed. His Nobel biography credits his staining of the granules in blood cells with laying the foundations of later work in haematology, the science of blood and its diseases. The ability to identify and count the different cells in a drop of blood, which made it possible to diagnose many blood diseases, grew directly out of his experiments with coloured chemicals.
Why it matters
The blood smear and white cell count, still used every day to diagnose infections, anaemias and leukaemias, rest on the staining principles Ehrlich worked out.
About Paul Ehrlich
Nobel-winning German Jewish physician who imagined the “magic bullet”, founded chemotherapy and, with Salvarsan in 1909, produced the first effective drug against syphilis.
More about Paul Ehrlich
- Paul Ehrlich named and characterised the mast cellWhile still a young scientist, Paul Ehrlich named and characterised the mast cell, the immune cell now known to drive allergic reactions.
- Paul Ehrlich's maxim is the first rule of drug designPaul Ehrlich summed up a basic law of pharmacology in four Latin words, corpora non agunt nisi fixata: a drug acts only when it is bound to its target.
- Paul Ehrlich's dyes revealed the blood-brain barrierPaul Ehrlich noticed that dyes injected into the bloodstream coloured nearly every organ except the brain, an early clue to the blood-brain barrier that protects our nervous system.
- Paul Ehrlich improved the tuberculosis test overnightThe day after Robert Koch announced the tuberculosis bacterium in March 1882, Paul Ehrlich improved Koch's method of staining it, making the deadly germ far easier to detect.
- Paul Ehrlich's "magic bullet" cured syphilisPaul Ehrlich imagined a "magic bullet" that would strike disease without harming the patient, and in 1909 his lab found Salvarsan, the first modern antimicrobial drug and first cure for syphilis.
- Paul Ehrlich treated malaria with a synthetic dyeNoticing that malaria parasites soak up methylene blue, Paul Ehrlich tried the dye as a treatment, and two patients' fevers subsided, an early step toward designed synthetic drugs.
- Paul Ehrlich foresaw antibodies and receptorsPaul Ehrlich's side-chain theory proposed that cells carry receptors that bind specific toxins, an idea about antibodies that helped earn him the 1908 Nobel Prize.
- Paul Ehrlich made diphtheria antitoxin reliableWorking with Emil von Behring in the 1890s, Paul Ehrlich devised ways to measure the strength of diphtheria antitoxin, so doctors could give children safe, reliable doses.
- Paul Ehrlich’s trypan red opened the attack on trypanosomesScreening over 100 dyes in Frankfurt, Paul Ehrlich’s team found trypan red, which killed trypanosomes in infected animals, an early chemotherapy victory that led to arsenic drugs.
Sources
- Paul Ehrlich Wikipedia
- Paul Ehrlich, Biographical NobelPrize.org
Another act of tikkun olam. This is part of tikkun olam, the Jewish idea of repairing the world, and every one of us can add to it.