MEDRADSC 2X03 Lecture Notes - Lecture 5: Interphase, Srf 1, Radioresistance
Document Summary
Can occur spontaneously without injury to cell or can be induced. Ordered sequence of events: stops communication, chromatin condenses (cleans up its stuff, nucleus fragments, cell condenses, breaks into pieces, fragments are phagocytosed by surrounding cells. When radiation-induced, may happen after several successful post-irradiation divisions. More common type of radiation-induced cell death. A survivor cell can undergo repeated cell divisions (cid:862)(cid:272)lo(cid:374)oge(cid:374)i(cid:272)(cid:863): a cell that can proliferate indefinitely and for a large colon from a single cell. Plating effiency is talking about how the cells divide normally. Eg. if 100 cells seeded& only 70 colonies were counted then the plating efficiency (pe) would be: pe = (# colonies counted/# cells seeded, pe = 70/100 or 70% for a particular strain. Graph of surviving fraction as a function of dose to colony (how radiosensitive or radioresistant it is) Normally obtained using data from in vitro experiments using established cell lines.