Ehrlich, desireable

Paul Ehrlich
Paul Ehrlich, 1915

Ehrlich, desireable is a qualitative assay detection of biologically important substances in the blood and urine. Based on non-specific color reaction between disreaction Ehrlich and some organic substances (pyrrole, cresol, indican, proteins containing amino acid tyrosine, tryptophan, histidine and others).
Desireable in the urine. Reagents: 1) detractive (0.5 g sulfanilic acid and 5 ml of 25% solution of hydrochloric acid in 100 ml of water); 2) 0.5% solution azotistykh sodium.
Procedure for execution of this reaction: to 4 ml I reagent add 1-2 drops II reagent, poured 4 ml of urine, then 1 ml of 10% solution of ammonia; the tube is closed with the cap and shake the liquid to foam. The sample is considered positive if pink or red coloring and negative at the yellow or orange. Positive reaction is observed in many febrile illnesses: abdominal and typhus, miliary tuberculosis, chlamydia, measles, the trichinosis , etc. In the presence of bilirubin in the urine appears with disreaction red staining of urine even before the addition of ammonia.
Desireable in the blood. Applied in the determination of bilirubin with which a mixture of detraction in a certain ratio gives red color. Desireable Ehrlich underlies most of the methods of quantitative and qualitative determination of bilirubin (see).

Ehrlich, desireable (P. Ehrlich) - color reaction between disreaction Ehrlich and a number of organic substances (pyrrole, cresol, indican and others), the incoming connection agogruppa (-N=N-), used for the quantitative determination of biologically important substances in the blood and urine.
Preparation of detractive: solution 5 g sulfanilic acid in 50 ml of strong hydrochloric acid (d=1,12) add water to volume of 1 l; for the obtained solution add 0.5% solution azotistykh sodium. This forms diasoftinsurance acid (Ehrlich reagent), which forms a colored compounds with some biologically important substances in the blood and urine.
Wide application desireable Ehrlich received in a clinic for qualitative and quantitative determination of bilirubin in the blood (see below). Detractive also used to determine tyrosine, histidine and histamine. Proteins, the molecule of which consists of the amino acid tyrosine, tryptophan and histidine, give with disreaction orange-red color. When defining certain substances as a component of colored compounds used not sulfanilic acid, and other cyclic compounds, for example in the determination of phenols in the blood and urine - parametroaren, in the determination of sulfonamides - 2R-acid etc.
Desireable in the blood. Bilirubin if desireable gives a characteristic red-violet color. This phenomenon was used for most of the methods of qualitative and quantitative determination of bilirubin in the blood. Currently most often used method of Andraseca, allowing to define separately fraction of bilirubin.
Reagents: (a) caffeine reagent: 5 grams of caffeine, 7.5 g benthological sodium and 12.5 g sodium acetate dissolve with a small stirring up in distilled water and add water to 0.1 l; b)detractive: first reagent 1 g sulfanilic acid is dissolved in a little water and add 15 ml of concentrated HCl, add water to 1 litre; the second solution, 0.5% solution azotistykh sodium.
Before use, mix 10 ml of the first reagent and 0.25 ml of a second. For determination of total bilirubin to 1 ml serum poured 3.5 ml of caffeine chemical and 0.5 ml of detractive, and in the determination of direct bilirubin to 1 ml of serum is added to 3.5 ml of physiological solution and 0.5 ml of detractive. A well-mixed, both samples after 5 minutes colorimetrate against compensation solution consisting of 1 ml serum, 3.5 ml of caffeine chemical and 0.5 ml of physiological solution at green filter. Indirect bilirubin is determined by subtracting from the total direct.
Desireable in the urine is in addition to the 10 ml of fresh urine and 10 ml of detractive and 2 ml of 10% solution of ammonia. After vigorous shaking there is a pink or Carmine-red color. The reaction is considered positive if painted not only liquids, but also formed foam. Yellow or orange indicates a negative result. In doubtful cases the formation of the next day sediment blue-green or black can be considered a positive response. Currently, this reaction is of no practical value, as it is non-specific and characteristic of many febrile diseases: and abdominal typhus fever, miliary tuberculosis, polyserositis, measles, chlamydia, pneumonia, diphtheria, erysipelas, trichinosis. In addition, drugs: opium, morphine, Dynin, Tofan, hexamethylenetetramine, rhubarb, heroin, prizerebel, salvarsan - give-like colouring, and drugs tannin, phenol and its derivatives, cresol, guaiacol and salol prevent reactions.