title: Assessment of the integrity of compounds stored in assay-ready plates using a kinase sentinel assay.
abstract: Sentinel assays are a convenient adjunct to LC-MS purity assessment to monitor the integrity of compounds in pharmaceutical screening collections over time. To assess the stability of compounds stored both at room temperature and at -20°C in assay-ready plates that were either vacuum pack-sealed using a convenient industrial vacuum sealing method or individually sealed using conventional foil seals, a diverse collection of &#126; 5,000 compounds was assayed using a robust biochemical kinase assay at intervals over a one year period. Assay results at each time point were compared to those of initial assay using a series of correlations of compound Percent of Control (POC) values as well as IC50 values of a subset of compounds in 200 nL or 500 nL plates. The fraction of hits in common between initial assays and assays at later time points ranged from 82% to 95% over one year and remained relatively constant over time with all storage temperatures or sealing methods tested. A majority of the hits that exhibited a consistent gradual trend to lower potency over one year storage were shifted to lower potency upon the rapid removal of DMSO solvent. Compound precipitation rather than compound decomposition is the likely reason for trends to lower potency for most such compounds over the storage period. Plates stored at room temperature featured a significantly higher fraction of hits that exhibited a trend to lower apparent potency than those stored at -20°C suggesting that this lower temperature is preferable for longer-term storage.
authors: Therapeutic Discovery, Amgen, Inc., 1120 Veterans Blvd., South San Francisco, CA 94080 USA.
authors: Ada
authors: A
authors: Chen
authors: Xiaoning
authors: X
authors: Zhao
authors: Laina
authors: L
authors: Mercer
authors: Cheng
authors: C
authors: Su
authors: Leeanne
authors: L
authors: Zalameda
authors: Yichin
authors: Y
authors: Liu
authors: Amanda
authors: A
authors: Lembke
authors: Heather
authors: H
authors: Eastwood
authors: Son
authors: S
authors: Dang
authors: Thim
authors: T
authors: Oung
authors: Xiaoyang
authors: X
authors: Xia
authors: Stephen W
authors: SW
authors: Young
authors: Shouhua
authors: S
authors: Xiao
authors: John D
authors: JD
authors: McCarter
mesh_terms: D002853:Chromatography, Liquid; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D004355:Drug Stability; D004356:Drug Storage; D013058:Mass Spectrometry; D012997:Solvents / Q000737:chemistry
chemical_list: D012997:Solvents; D004121:Dimethyl Sulfoxide