Abstract: Disclosed are methods for non-destructively measuring in vitro the effect on cellular metabolism of the addition to animal cells in culture of a soluble molecule potentially capable of perturbing the biological state of the cells, such as a drug or drug candidate, a toxin, a ligand known or suspected to bind to a cell surface receptor, a nutrient, a cytokine, a growth factor, a chemokine, a metabolism inhibitor or stimulator. Also disclosed are methods for measuring cell viability, vitality, or quality, e.g., in anticipation of the execution of an experiment on the cells. The measurements are done by observing alteration in the rates of consumption or production of extracellular solutes related to aerobic and anaerobic cellular metabolism, such as oxygen, protons, nutrients, carbon dioxide, lactate, or lactic acid. The methods are particularly useful in drug discovery efforts, such as cancer drug discovery and searches for modulators of cellular metabolism.

Abstract: The invention relates to methods and compositions useful in screening for modulators of IgE synthesis, secretion and switch rearrangement.