BS EN ISO 17099:2017 pdf free

BS EN ISO 17099:2017 pdf free.Radiological protection
In BS EN ISO 17099, the frequency of micronuclei in cytokinesis block binucleated lymphocytes in cultured human peripheral blood lymphocytes scored by microscopy is used for dose estimation after suspected exposure to ionizing radiation.
Lymphocytes are cultured by a method that permits once- divided cytokinesis block cells to be recognized by their binucleated appearance for analysis. This requires whole blood or lymphocytes separated from the other blood components to be incubated in culture medium with a mitogen that would enable scoring of micronuclei in first-generation binucleated cells. A cytokinesis blocking agent, cytochalasin-B,is added at least 6 h before the first mitosis commences to arrest dividing lymphocytes at the binucleated cell stage after nuclear division is completed. The duration of the cell culture and the timing of addition of the arresting agent are optimised to ensure an adequate frequency of binucleated cells.
Binucleated cells are recovered from the cultures by centrifugation, placing in a hy potonic salt solution and fixing in a mixture of methanol and acetic acid. Fixed cells are placed on microscope slides and stained. In the case of isolated lymphocytes, it is also acceptable to prepare slides by cytocentrifugation of cells onto slides, followed by air-drying, fixation with methanol, and staining. The exact protocol for cell culture, harvesting binucleated cells and staining employed by a CBMN laboratory should be formally documented.
Microscope slides containing stained cells are methodically scanned to identify suitable binucleated cells. The frequency of micronuclei observed in an appropriate number of scored binucleated cells is converted to an estimate of radiation dose by reference to calibration data.
The laboratory should be well-equipped with the required bio-hazard units, tissue culture, and standard laboratory equipment for lymphocyte tissue culture, cell separation, slide preparation, and microscopy scoring of cells and subcellular structures, such as micronuclei. The laboratory should maintain quality assurance documents including those describing periodic calibration of the equipment used for cell culture such as laminar flow hoods, pipettes, incubator, etc.BS EN ISO 17099 pdf download.