Molecular Screening and Protein Expression Facility

Overview of Services

The Molecular Screening and Protein Expression Facility provides biochemical and cell-based assay development expertise to establish assays suitable for high-throughput screening and compound profiling.  In addition, we offer protein expression services in insect cells.  Other hosts such as bacteria and mammalian cell lines as well as protein purification are offered on a case by case basis.  In addition, the facility manages glycerol stocks the TRCN shRNA library and individual clones are available upon request.


We can establish binding assays which measure protein-protein, protein-ligand, or protein-nucleic acid interactions using fluorescence polarization, time-resolved fluorescence (HTRF), and AlphaScreen technologies in both 96- and 384-well formats.  Enzyme assays using fluorescent or luminescent substrates can also be developed in both kinetic and endpoint formats depending on the substrate.  We have a surface plasmon resonance (SPR) system, the Biacore T200, which enables us to investigate biochemical interactions using label free technology and to determine the kinetics and stoichiometry of these interactions.  In addition to biochemical assays, we can also establish cell-based assays to investigate signaling pathways, protein expression, and cytotoxicity (mitochondria depolarization, caspase activation, live/dead, etc) using similar technologies.  We also have a high-content imaging system, which can collect and analyze data on fixed cells stained with fluorescent markers in 96-well format to identify cellular morphology changes in response to treatment. 


We have a collection of ~100,000 compounds which can be screened using our liquid handling systems after the development of a suitable assay to find starting points for lead optimization.  After the identification and confirmation of these active compounds, Joseph Salvino’s chemistry team can modify these compounds to increase potency and selectivity at the target of interest. 


Lastly, we provide user access to some of our equipment, such as cell culture hoods and microflow systems.  The Biotek Microflow system is a ‘non-contact’ liquid dispenser which can dispense volumes as low as 5 uL to 96-well or 384-well plates.  In addition, we also offer user access to the Envision plate reader, which can measure absorbance, fluorescence, FP, HTRF, AlphaScreen, and luminescence in 96-and 384-well formats.  Trained users are also able to use our Biacore T-200 and the Operetta (high-content imaging system for fixed cells)



Joseph Salvino, Ph. D.
Scientific Director


Joel Cassel
Managing Director




Barbara Niedziolka


Hours of Operation and Location  

Hours Location

8:00AM - 5PM
Monday - Friday          


The Wistar Institute
Molecular Screening and Protein Expression Facility, Rooms 322 and 355
3601 Spruce Street
Philadelphia, PA 19104

Links and Resources



Name Role Phone Email Location
Joseph Salvino, Ph. D.
Scientific Director
(215) 495-6866
Joel Cassel
Managing Director
(215) 495-6885

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