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D Wittekind

Publications and source records attributed to D Wittekind.

7 recordsLinked to original sources
PubMed1979

On the nature of Romanowsky dyes and the Romanowsky-Giemsa effect.

This paper reviews the nature of Romanowsky staining and the relationship between Romanowsky dyes and the Romanowsky-Giemsa effect (RGE). On blood and bone marrow smears the RGE is characterized by a purple colouration of nuclei and neutrophil granules. The nuclear purple contrasts strongly with the blue cytoplasmic staining of cells rich in RNA. Requirement for the occurrence of RGE are: I A cationic dye: The best dye is azure B and, though azure A gives the nuclear purple colour, the cytoplasmic blue is inferior. No other cationic dye such as methylene blue is suitable. 2 An anionic dye: Most commonly eosin Y is used, but it can be replaced by the erythrosins. Full halogenation of the fluorescein (four atoms of bromine or iodine) is not necessary. Phloxine and rose bengal are unsuitable. 3 An appropriate substrate: These are proteins with acidic side groups or proteins bound to a polyanion. For the interaction with the dyes substrates must provide a suitable three-dimensional network which is why the RGE is not obtained in solutions. A tentative theory of RGE is advanced and briefly discussed.

Azure Stains↗
PubMed1979

[Simplification of the Papanicolaou stain which is easily reproducable (author's transl)].

A simple and well reproducable modification of the Papanicolaou stain is reported. The most important modification is the replacement of the natural stain hematoxyline by the qualitively excellent synthetic stain thionin which is immediately added to the alcoholic fixation solution for a fixation stain. The high labor intense alternation between alcohol water and alcohol is thus eliminated. The quality of the nuclear staining is very good. The fixation staining with thionin without counter-staining of the cytoplasma may be used for a rapid thionin stain which gives sufficient cytoplasmatic staining by the thionin for a rapid cytological smear for cancer. The counter-stain of the cytoplasma was also simplified. The over-all staining of this simplification of the pap smear is comparable to that of the original papanicolaou stain. This modification of the papanicolaou stain fulfills requirements which a stain in competition with the original papanicolaou stain should have. 1. The modification is qualitively equal to the original method, 2. the staining method is simpler, 3. the staining method is well reproducable, 4. the staining method is more economical.

Female↗
PubMed1976

[Can azur-B eosin replace the May-Grünwald-Giemsa stain?].

A new method is described for staining blood and bone marrow smears. It is characterized by the presence of only two dyes, purified azure B and eosin in methanol, as stock solutions. Staining results are equivalent to those obtained by using the traditional dye mixtures according to May and Grunwald, Giemsa, Leishman or Wright. Different from these azure B-eosin staining can be standardized and is easier to be handled. Correlations between the azure-B-eosin and May-Grunwald-Giemsa (MGG) staining methods are briefly discussed.

Blood Cell Count↗
PubMed1975

The azure dyes: their purification and physicochemical properties. II. Purification of azure B.

A method is described for the purification of the dye azure B in quantities sufficient for biological staining experiments on a larger scale. The method is based on the use of column chromatography. Two columns are employed. In column A with silica gel as adsorbent the azure B fraction is isolated from a suitable substrate ('technical' azure B gained by a modification of Bernthsen's synthesis of methylene blue, or polychrome methylene blue) using an acetate-formate mixture as eluent. In column B, on an Amberlite polymeric adsorbent (XAD-2) the acetate-formate anions are exchanged in chloride. Regeneration of both columns is possible: KMnO4, Na2S2O4 and water are run through column A; 5% NaOH, methanol and water through column B. Purification of azure B on economic terms is thus attained. The opinion is expressed that this method is also applicable to the purification of other cationic dyes.

Chlorides↗