Responses to Questions

B.1 TITLE

EPA Multiplexed Transcription Factor Profiling of the ToxCast Compound Library IDIQ

B.2 BRIEF DESCRIPTION OF SERVICES/SUPPLIES

Use of cellular assays to define activity of compounds against a broad spectrum of transcription factor targets is being used for screening the environmentally relevant chemical universe with program such as Tox21. The ability to multiplex many transcription factors into a single assay has proven to not only be cost effective, but also provides integrated information from a single well. The EPA is continuing to evaluate this approach to build methods prioritizing compounds for additional screening and testing based on predicted hazard and potential toxicity. This project is entitled the ToxCast Program.

The EPA has a need for contractor-supplied laboratory testing and analysis services in support of this program. The contractors shall use technologies aimed at profiling, in a multiplexed fashion, transcription factor activity in cell lines and cell culture conditions appropriate for toxicity testing when performing these services. Assays may be either mono- or co-culture system, but each assay shall address multiple transcriptional factor targets within a single well.

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