Service details and sample submission
This commonly used shake flask protocol is based on the use of Millipore Multiscreen solubility filter plates or centrifugation followed by UV-Vis quantitation of dissolved compounds. Microplate reader SpectraMax Plus (Molecular Devices) is used in our lab for UV-Vis measurements. LC-MS/MS quantitation (API3000 mass-detector, AB Sciex) can be also done for poorly UV-absorbing compounds, mixtures and compounds prone to degradation. Solubility measurements are normally performed from DMSO stock solutions (but can be also done from powders for thermodynamic solubility measurements). LC-MS/MS is the preferred detection method in case of thermodynamic measurements.
Typical assay conditions and details are as follows:
– 2 hrs shaking time at 25°C in an aqueous buffer, for kinetic solubility measurements;
– 18 hrs shaking time at 25°C, for thermodynamic solubility measurements.
The assay is run in duplicates. One or two reference compounds are included in each test batch. Other assay protocols are available upon request.
Sample requirement is at least 100 µL of 20 mM stock compound solutions in DMSO for kinetic solubility measurements, and 2 x 2 µmoles of dry compound for thermodynamic solubility measurements. We do not need to know structures of the molecules for ADME testing. However, we ask our customers to provide brutto formulas for all studies involving MS detection.
Full study report is provided (an example report is shown).