Kisaalita, William S.Bowen, John M.2025-04-152025-04-151997Kisaalita, W. S., & Bowen, J. M. (1997). Effect of medium serum concentration on N1E-115 neuroblastoma membrane potential development. In vitro cellular & developmental biology. Animal, 152-155.https://www.jstor.org/stable/4294566https://nru.uncst.go.ug/handle/123456789/10757Propidium iodide (PI) emissions were determined by PMT2 after pas-sage through a 610-nm long-pass filter. SSC was determined by PMT4. FALS signals were linearly amplified with a gain of 2. Unless otherwise stated, 50,000 events were counted at an approximate rate of 200 events per second. Because subcellular debris has low FALS, this parameter was used to gate out these particles. Oxonol fluorescence analysis was restricted to events that were PI-negative, since dead or dying cells are stained by PI. To compare results for experiments conducted at different times, polystyrene fluorospheres (Coul-ter Corporation, Hialeah, FL) were used to set the PMT,(oxonol signal) and PMT4 (SSC signal) at channel numbers of 35? 1 and 100? 2, respectively, before each experiment. DMSO was included in this study as a positive control, because it is considered one of the most potent enhancers of electrical excit-ability among other chemical differentiating agents (Spector and Baumgold, 1982). Aminopterin was also included as a positive con-trol. Aminopterin blocks the normal biosynthetic pathway by which nucleotides are made (Henderson et al., 1965) and therefore was expected to kill off most if not all the dividing (nondifferentiating) cells and thus yield the most differentiated cells. Previous Vm results obtained by intracellular and patch clamp recording techniques on a few cells have indicated that the transition from low to high Vm occurred between 7 and 10 days (Kimhi et al., 1976; Santone et al., 1986; Baumgold and Spector, 1987; Cosgrove and Cobbett, 1991).enArticle