DMSO is also used to dissolve test compounds in "in vitro" drug discovery and drug design screening programs (including high-throughput screening programs). This is because it able to dissolve both polar and nonpolar compounds, can be used to maintain stock solutions of test compounds (important when working with a large chemical library), is readily miscible with water and cell culture media, and has a high boiling point (this improves the accuracy of test compound concentrations by reducing room temperature evaporation). One limitation with DMSO is that it can affect cell line growth and viability (with low DMSO concentrations sometimes stimulating cell growth, and high DMSO concentrations sometimes inhibiting or killing cells).