T he insides of cells are crowded. Fig. 1A is a dramatic representation of the fact that macromolecules occupy 30% of the cellular volume, with their concentrations reaching 300 g/L (1). For comparison, the concentration of protein in an egg white is only one third of that value. However, almost everything we know about biological macromolecules in solution comes from data acquired under condit...

The capability of certain drugs to cause immune-mediated drug hypersensitivity reactions in susceptible individuals has initiated a search for pre-clinical screening tools to identify immunosensitizing drugs. Since most drugs are taken orally, hazard assessment of their immunosensitizing potential should include oral exposure models. In this study, the predictive value of the reporter antigen (...

We describe a method for preparing purified erythroblastic nests in large numbers (approximately 10(6)/run) in three steps: (1) induction of splenic erythropoiesis in mice, (2) preparative differential centrifugation for the removal of erythrocytes and single cells from spleen cell suspensions, and (3) sedimentation in an isokinetic gradient of Ficoll 400 in Joklik's modification of minimum ess...

The surface structure of myeloma cells was examined by scanning electron microscopy. The cells were collected from the pleural effusion of a multiple myeloma patient and purified by Conray-Ficoll gradient sedimentation. The cell size ranged from 8 mu to 12 mu in diameter and the microvilli were from 0.8 mu to 1.2 mu in length. The surfaces of the majority of the observed myeloma cells were more...