News from the Biological Stain Commission, No. 17.

In the 17(th) issue of News from the Biological Stain Commission (BSC) under the heading of Regulatory affairs, the Biological Stain Commission's International Affairs Committee presents information from the 20(th) meeting of ISO/TC 212 Clinical laboratory testing and in vitro diagnostic test systems held on October 15 - 17, 2014 in Toronto, Canada, and from the 29(th) meeting of CEN/TC 140 In vitro diagnostic medical devices held on February 3, 2015 in Berlin, Germany.

News from the Biological Stain Commission, no. 16.

In the 16(th) issue of News from the Biological Stain Commission (BSC) under the heading of Regulatory affairs, the Biological Stain Commission's International Affairs Committee presents information from the 28(th) meeting of CEN/TC 140 In vitro diagnostic medical devices held on October 23, 2013 in Berlin, Germany. Information is also presented from the 19(th) meeting of ISO/TC 212 Clinical laboratory testing and in vitro diagnostic test systems held on October 19 - 21, 2013 in Singapore.

News from the Biological Stain Commission no. 15.

In the 15(th) issue of News from the Biological Stain Commission (BSC), under the heading of Regulatory affairs, the Biological Stain Commission's International Affairs Committee presents information from the plenary meetings of the International Standards Organization ISO/TC 212 Clinical laboratory testing and in vitro diagnostic test systems held on August 22-24, 2012 in Berlin, Germany. An additional discussion of the use of food dyes in India also is included.

News from the Biological Stain Commission no. 13.

In the 13(th) issue of News from the Biological Stain Commission (BSC) under the heading of Regulatory affairs, the Biological Stain Commission's International Affairs Committee presents information from the first plenary meeting of the International Standards Organization ISO/TC 212 Clinical laboratory testing and in vitro diagnostic test systems held on 17-19 October 2011 in Las Vegas, Nevada.

News from the Biological Stain Commission no. 12.

In this 12(th) issue of News from the Biological Stain Commission (BSC) under the heading of Regulatory affairs, the Biological Stain Commission's International Affairs Committee presents information from the meetings of ISO/TC 212/WG 1 Quality and competence in the medical laboratory and ISO/TC 212/WG 3 In vitro diagnostic products both held on 2 - 3 June 2010, plus information on the second plenary meeting of ISO/TC 212 Clinical laboratory testing and in vitro diagnostic test systems held on 4 June 2010. All meetings took place in Seoul, Republic of Korea. Finally, information is provided concerning the 25(th) meeting of CEN/TC 140 In vitro diagnostic medical devices held on 23 June 2010 in Berlin, Germany.

News from the Biological Stain Commission No. 11.

The 11th issue of News from the Biological Stain Commission (BSC) provides our first impressions of the REACH and ECHA programs. We intend to give a more thorough account of what these important programs actually mean in later editions of News from the Biological Stain Commission. Under the heading of Regulatory Affairs, the Biological Stain Commission's International Affairs Committee presents information from the opening session of the meeting of the International Standards Organization ISO/TC 212 Clinical laboratory testing and in vitro diagnostic test systems held on 2-4 June 2010 in Seoul, Republic of Korea.

News from the Biological Stain Commission No. 10.

In the 10th issue of News from the Biological Stain Commission (BSC), under the heading of Regulatory affairs, the Biological Stain Commission's International Affairs Committee presents information from the meeting of ISO/TC 212/WG 1 held in London, UK, on 16-17 November 2009. Furthermore, the items ISO CEN Vienna Agreement and CEN Annex Z are explained in more detail.

News from the Biological Stain Commission No. 5.

In this fifth issue of News from the Biological Stain Commission (BSC), under the heading of Regulatory Affairs, the BSC's International Affairs Committee provides more information from the meeting of the International Standards Organization ISO/TC 212 Committee that took place on June 2-4, 2008 at Vancouver, Canada. In addition, we give an update on the current situation regarding the supplies of hematoxylin.

News from the Biological Stain Commission.

In the three earlier editions of News from the Biological Stain Commission (BSC), under the heading of "Regulatory affairs," the BSC's International Affairs Committee reported on the work of Technical Committee 212, Clinical Laboratory Testing and in Vitro Diagnostic Test Systems of the International Standards Organization (ISO/TC 212) and its working groups, WG 1, WG 2 and WG 3. In this issue of News from the BSC, H.O. Lyon provides information from the annual meeting of ISO/TC 212 that took place June 2-4, 2008 in Vancouver, British Columbia, Canada. In addition, under the heading of "Certification," J.A. Kiernan examines the certification procedure for thionine used by the BSC laboratory in Rochester, NY.

Standardization and standards for dyes and stains used in biology and medicine.

The reasons for standardization and the preparation of standards for dyes and stains are presented. The national, regional and international standardization agencies are described in detail prior to a consideration of why standards should be prepared for the field of biomedical staining. An outline is given of the standards for information supplied by the manufacturer for in vitro diagnostic reagents for biological staining, published by the European Committee for Standardization (CEN) in 1999, and in a practically unaltered form by the International Organization for Standards (ISO) in 2002. A more detailed description is given in Appendix A of the rules governing the work of the European Committee for Standardization (CEN) and of the technical co-operation between the International Organization for Standardization (ISO) and CEN (The Vienna Agreement). Finally, a short list of abbreviations used by CEN and ISO is included as Appendix B.

Methyl green-pyronin Y staining of nucleic acids: studies on the effects of staining time, dye composition and diffusion rates.

Since the introduction of the methyl green-pyronin Y procedure as a differential histological stain more than 100 years ago, the method has become a histochemical procedure for differential demonstration of DNA and RNA. Numerous variants of the procedure have been suggested, and a number of hypotheses have been put forward concerning kinetics and binding mechanisms. Using both filter paper models containing DNA, RNA or heparin and histological sections, we have attempted to evaluate the kinetics of staining and the role of staining time for methyl green and pyronin Y by applying the dyes individually, simultaneously and sequentially. The results are presented as color charts approximating the observed staining patterns using a computerized palette. Our results indicate unequivocally that the differential staining is not time-dependent, but that it is dictated by the relative concentrations of methyl green and pyronin Y and by the pH of the staining solution.

Standardized staining methods: Feulgen-Rossenbeck reaction for desoxyribonucleic acid and periodic acid-Schiff (PAS) procedure.

A project group working under the European Confederation of Laboratory Medicine (ECLM) presents recommendations for standardized procedures for the Feulgen-Rossenbeck-Schiff and the periodic acid-Schiff (PAS) reactions on cytological and histological material. The advantages and disadvantages of such standardized procedures are presented here in a preamble. Both users and manufacturers are encouraged to give their opinions with a view to achieving consensus on these procedures and on how further work on these lines may proceed.

Dye purity and dye standardization for biological staining.

This review starts with a short discussion of what is meant by a pure dye and a brief description of how dyes are produced. A listing of the types of impurities encountered in dyes is made, followed by technical investigations and assessments of dyes and their impurities including methods for separating, identifying and assaying dye components. In the second part of the review, descriptions are given of the standardized staining method approach using standard staining methods for assessing stains, and practical responses to stain impurity including commercial quality control, third-party quality control and standardization of reagents, protocols and documentation. Finally, reference is made to the current state of affairs in the dye field.

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

The 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.

Simultaneous quantification of DNA and RNA in tissue sections. A comparative analysis of the methyl green-pyronin technique with the gallocyanin chromalum and Feulgen procedures using image cytometry.

For simultaneous cytophotometric measurement of DNA and RNA, the standardized Methyl Green-Pyronin Y technique is an obvious choice. It is, however, first necessary to correlate the uptake of Pyronin Y to the staining intensity of RNA. The material consisted of paraffin sections of formalin- or Carnoy-fixed rat liver. The sections were pretreated with water, buffer, deoxyribonuclease, ribonuclease, or both enzymes in sequence, and stained with the standardized Methyl Green-Pyronin Y procedure, Gallocyanin chromalum, or the Feulgen reaction. Sections stained directly without pretreatment served as controls. Staining intensities were measured with an image analyser for cell nuclei, nucleoli and cytoplasm. After deoxyribonuclease treatment, nuclear staining intensity with Methyl Green, Gallocyanin chromalum, and Schiff's reagent dropped nearly to zero. The same was seen for both nucleoli and cytoplasm with Pyronin Y and Gallocyanin chromalum after ribonuclease treatment. Staining intensity of Pyronin Y correlated directly with that of Gallocyanin chromalum for nucleoli and cytoplasm. After ribonuclease treatment, a direct correlation was found between the nuclear staining intensity of Methyl Green and nuclear absorption of Gallocyanin chromalum. We conclude that the standardized Methyl Green-Pyronin Y stain is reliable for the simultaneous quantitative assessment of both RNA and DNA. The simplicity of this technique makes it a valuable tool even for daily routine.

The impact of different fixation procedures on staining of macromolecules in a microtiter system.

The effects of formaldehyde, glutaraldehyde, methanol, Clarke's fixative and microwave irradiation on the quantitative staining of proteins (Naphthol Yellow S) and nucleic acids (Ethyl Green-Pyronin) in a cell culture system have been investigated. Overall, glutaraldehyde rapidly yielded the highest and most consistent levels of staining when compared to all other chemical fixatives. Although microwave irradiation was found to be uneven, 4 min exposure to 700W was found to give higher levels of protein staining than those achieveable with glutaraldehyde. Time-dependent processes were observed with all procedures. In addition, dissociations in the trends of protein and nucleic acid staining were observed. It is suggested that these results demonstrate fixation events that have not previously been resolved from the effects of reagent penetration into tissue blocks.