Services

The UPENN High-throughput Screening Core service structure is defined by two levels:

  1. Fee-for service which includes reagents, and the execution of screening assays that do not require further optimization or development of custom analysis procedures.
  2. Collaborative projects include diverse contributions from the HTSC. For example new assay development, optimization in complex contexts, primary cell models, custom analysis pipelines and advanced data analysis to interpret large data sets would all be collaborative.

Services include the following and are briefly described:

Reagents

Diverse reagents can be purchased from the core

Custom Libraries

  • Small-scale libraries can be purchased and arrayed
    • Genetic and small molecule

Consultations

  • Core Directors broadly cover the core’s capabilities, policies, specific discussion about the screening project/assay, pricing, anticipated timelines, and expectations.  Initial consultations require Principal Investigators to attend in addition to trainees that will be working on the project provided free of charge to investigators

Grant Applications and Letters of Support

  • The Core Directors encourage investigators to collaborate with the core when submitting grants that propose a screening project.  Core Directors will assess the scope of project to ensure it fits within the capabilities of the core, provide a Budget to cover the costs of screening, technical writing for the proposed screening project to be included with the Experimental Approach, and a Letter of Support. Investigators are encouraged to contact the Core Director at least one month in advance of the submission deadline.

Assay Development

  • Develop assay with investigators amenable to HTS.

Optimization

  • Core staff will optimize assay conditions for miniaturization in 384W plates. For biochemical screens and cell-based screens. Cell density, incubation time, DMSO sensitivity, and assay reagent requirements (i.e. volumes, antibodies, antibody dilutions, etc.) will be tested to maximize the accuracy and precision of an assay’s response to negative and positive control conditions.  We use the Z’ factor to assess the robustness and fitness of an assay for HTS.  We use CVs of control replicates (<10%), Signal-to-background (S:B), and CV of S:B as additional metrics to assess an assay’s readiness for HTS.

Screen Implementation

  • Pilot screens: upon validation of assay conditions fit for HTS, the core will run a pilot screen to assess the assay’s performance during high-throughput screening conditions.  We will use the Z’ factor, CVs of control replicates (<10%), and Signal-to-background (S:B) to assess the assay’s robustness across assay plates.
  • Primary screens: assays validated within the UPenn HTSC can be screened against our larger collections.  HTSC campaigns of larger libraries are routinely completed as installments to ensure the fidelity and robustness of assay. We will use the Z’ factor, CVs of control replicates (<10%), and Signal-to-background (S:B) to assess the assay’s robustness across assay plates.  

Analysis

  • All data acquired within the HTSC are analyzed. Users are provided a data package that includes annotation of raw and normalized biological data with compound information and a list of candidate hits based on standard non-parametric criteria (e.g. z-score) that are in line with standard industry practices.

Validations

  • Primary screening data can be validated using a variety of assays.
    • Orthogonal assays
    • Cytotoxicity assays
    • Dose responses
    • Counter screens