D Wittekind

Standardization of reagents and methods used in cytological and histological practice with emphasis on dyes, stains and chromogenic reagents

SummaryThe need for the standardization of reagents and methods used in the histology laboratory is demonstrated. After definitions of dyes, stains, and chromogenic reagents, existing standards and standards organizations are discussed. This is followed by practical instructions on how to standardize dyes and stains through the preparation of reference materials and the development of chromatographic methods. An overview is presented of the problems concerned with standardization of the Romanowsky-Giemsa stain for cytological and histological application. Finally, the problem of how to convince routine dye and stain users of the need for standardization in their histology laboratories is discussed.

Dye standards, Part I: terminology and general principles

Kobenhavns Kommunes Hvidovre Hospital, Department of Pathology, 134 Copenhagen, Denmark 2 Anatomische AnstalL Ludwig-Maximilians-Universitdt, Mffnchen, Germany 3 Laboratoria voor Medische Biochemie en voor Klinische Analyse, Gent, Belgium 4 Royal Postgraduate Medical School London, UK 5 Sigma Diagnostics, Deisenhofen, Germany 6 Serva GmbH, Heidelberg, Germany 7 Centre for Biomedical Sciences, Liverpool Polytechnic, Liverpool UK Department of Oral Medicine, University of Wales, Cardiff, UK 9 Institute for Pathology, H~lsouniversiteL Linkdping, Sweden so Department of Veterinary Anatomy, Royal Veterinary and Agricultural University, Copenhagen, Denmark 1i Department of Biomedical Science, The University of Shefjqeld, Sheffield, UK ~2 Department of Cytology, Chafing Cross Hospital, London, UK 13 Anatomisches InstituL University of Freiburg, Germany i4 E. Merck, Darmstadt, Germany

Stability study of Azure B, Eosin Y and commercial Romanowsky Giemsa stock solutions using high performance liquid chromatography.

SummaryThe stability of Azure B and Eosin Y in stock solutions of the individual compounds as well as in mixtures of the two dyes was studied. The purpose of the study of these two essential constituents of the Romanowsky Giemsa stain, commonly used in cytology and histology, was to select a stable mixture as a definitive stock solution. Two specific high performance liquid chromatographic methods were used to monitor qualitative and quantitative changes in solutions. Several parameters influencing the stability of Azure B were examined e.g. the type of counter ion the presence of Eosin Y and the type of solvent used. The second part focused on the stability of Eosin Y in mixtures with different cationic dyes submitted to high temperatures. In conclusion, an Azure B SCN-Eosin Y acid mixture in dimethylsulphoxide (concentrations 0.75% and 0.12%, respectively) was selected as being the most appropriate composition of a stock solution for the Romanowsky Giemsa stain.