What does it mean to use DMSO as a dissolvant in biology experiemnts?
Usually such compounds are dissolved in DMSO to make a concentrated stock solution (e.g. 1000x), which is then diluted into the culture medium. Often, the compound is soluble in water at this lower dilution, but not at the higher concentration required to make a stock. Sometimes the compound has low solubility in water and much of it precipitates. This still lets us test the effect of the fraction that remains soluble.