Stability In Buffer

This assay is used to determine the chemical stability of a test article in buffer.

Required from Sponsor

  •  Either a minimum of 100 µL of test article at 10 mM in DMSO or 2 mg of powder
  • Exact molecular mass of test article and its salt form
  • MSDS or handling and storage information, e.g., light sensitive, store at -20°C, etc.


  •  A table of percent remaining of test article at each time point
  •  Half-life, as applicable


  •  Test article dissolved in buffer at 1 μM

Assay System

  •  50 mM phosphate buffer, pH 7.4

Assay Conditions

  •  Discrete incubation for each sampling time point (n=1 per time point) in buffer at 37°C
  •  Add acetonitrile directly to discrete incubation at 0, 15, 30, 60, and 120 minutes
  •  Use LC-MS/MS to determine the peak area response ratio (peak area corresponding to test article divided by that of an analytical internal standard) without running a calibration curve


  1. The results from this assay will be provided to the sponsor in the ExpressPlus report format, which may include graphical representations of data and comparison with historical data for reference articles.
  2. The buffer is 50 mM phosphate buffer, pH 7.4.