Methyl Orange, 0.1 Percent (w/v) Aqueous Indicator Solution, (U.S.P. Test Solution) is a Spectrum solution concentrate that allows the preparation of fresh, reliable standard volumetric solutions quickly and accurately. Simply dilute the desired USP test solution concentrate to the specified volume (carefully following instructions provided with the package) and the resulting solution will have an exact concentration within 0.1%. Spectrum USP test solution concentrates are relied upon for fast, accurate results in life sciences and pharmaceutical quality control applications.