Dragendorff's reagent: Historical perspectives and current status of a versatile reagent introduced over 150 years ago at the University of Dorpat, Tartu, Estonia.

The well-known Dragendorff's reagent (DR) was introduced by an Estonian-German Professor Johann Georg Noel Dragendorff (1836-1898) in the middle of the 19th century (1866). Dragendorff, who was a full-time professor in pharmacy at the university of Dorpat (Tartu) used his reagent originally for the rapid screening of herbal products to find traces of alkaloids. DR is a solution of potassium bismuth iodide composing of basic bismuth nitrate (Bi(NO3)3), tartaric acid, and potassium iodide (KI), and when contact with alkaloids DR produces an orange or orange red precipitate. In this review article, we make a short historical overview on the biography and scientific research work of Professor Dragendorff at the University of Dorpat. The chemistry, method of preparation, mechanism of action, and practical uses of DR in various disciplines in various European countries including the Baltic countries (Estonia, Latvia, Lithuania), Finland, Ukraine, Moldova, and in Asia (Vietnam), are also discussed. Over several decades, DR and its modifications have found uses in many new applications and disciplines, and a number of commercial DRs are also currently available on the market. Today, DR is used for example in the production of surfactants, where non-ionic surfactant is precipitated in water solution with modified DR (KBiI4+BaCl2+glacial acetic acid). Total six different potassium iodobismuthate (DR) solutions are also presented in the European Pharmacopoeia. In conclusion, DR (after more than 150 years of its invention in Estonia) has still an important role in pharmaceutical and related sciences all over the world.

[First domestic production of transaminase assay reagents].

Ultraviolet absorption has continued to improve and has become a commonly used method. The development of automated instruments has also contributed to its use, making the Reitman-Frankel Method retire from the prominent stage it once occupied. While the Camen Method was indicated to be short of substrates, it is now used after incorporating improvements proposed from various countries, including the JSCC recommendation from Japan, as a titration method for the enzyme reference materials. The JSCC Common Standards Method was further provisioned through detailed examinations ot its reagents and processes, and is utilized under strict conditions. Standardization has thus evolved from more technique to what includes reference materials.

Luis Simarro Lacabra [1851-1921]: from Golgi to Cajal through Simarro, via Ranvier?

Knowledge of cerebral structure and function in its modern form can be traced to the neurone doctrine based largely on the work of Santiago Ramón y Cajal [1852-1934] and his lifelong exploitation of the Golgi method. Cajal openly acknowledged his debt to the neuropsychiatrist Luis Simarro Lacabra [1851-1921] who introduced him to the method in 1887, and recalled that the sight of the silver-impregnated nerve cells was the turning point which led him to abandon general anatomy and concentrate on neurohistology. Simarro, who dissipated his free time in trying to improve not only the scientific but also the political world around him, was able to produce exciting Golgi preparations of the cerebral cortex after he returned from voluntary exile in Paris from 1880 to 1885. Certainly it was there that he learned the methods of experimental histology from Louis-Antoine Ranvier [1835-1922] whose laboratory exercises, in the guise of lectures, he attended assiduously.

Ruthenium red and the bacterial glycocalyx.

Ruthenium red, a promising cationic reagent for electron microscopy (EM), has long been an important tool in histology. The reagent was initially used by botanists as a semispecific stain for pectic substances, but it has gradually been embraced by investigators in microbiology and the animal sciences as a stain for anionic glycosylated polymeric substances. Luft developed a reliable method and demonstrated that ruthenium red was a useful reagent for visualizing ultrastructural detail. Many investigators, using modifications of Luft's approach, have identified numerous applications for this important reagent. Ruthenium red has been used to show the ultrastructural detail of bacterial glycocalyces. Strong, sharp and consistent observations of this ultrastructural component of the bacterial cell have given a better understanding its fibrous anionic matrix. Any variations in staining owing to artifactual alteration of the fine delicate ultrastructural features have been overcome by incorporation of diamine lysine into ruthenium red methods, thus providing flexible processing times under less than ideal laboratory sampling conditions. Ruthenium red has broad utility in the biological sciences, and in combination with lysine, it is an excellent EM stain for enhanced visualization of bacterial glycocalyx from culture or from clinical specimens.

[Ehrlich's benzaldehyde reaction (with urobilinogen) 80 years later]. / Uber Ehrlichs Benzaldehyd-Reaktion (auf Urobilinogen) nach 80 Jahren.

The colour reaction of di-methyl-amido-benzaldehyde with metabolites in urine (especially with urobilinogen), discovered and published by Paul Ehrlich 80 years ago has lost nothing of its significance as a simple, practical, quick, qualitative test. It provides a diagnostic means in liver diseases, hemolytic processes, occlusion of the common bile duct, carcinoid and porphyrinopathies--of course, within the framework of the whole clinical picture. Despite the technical simplicity of the test, certain rules have to be adhered to. Ehrlich's aldehyde reagent has also won importance in chromatography. The modern test-strip technique permits an easy and rapid examination for urobilinogen (and bilirubin).