SRC-1 (676-700), biotinylated, also known as biotin-SRC-1, or biotinylated steroid receptor coactivator-1 peptide, is a biotinylated 25-mer peptide derived from amino acids 676-700 of the transcriptional coregulatory protein human nuclear receptor coactivator SRC-1. SRC-1 (676-700), biotinylated has been used in AlphaScreen, time-resolved fluorescence (TRF), and time-resolved fluorescence energy transfer (TR-FRET) assays for various nuclear receptors including assays for the ROR family proteins RORalpha, RORbeta and RORit, a farnesoid X receptor (FXR) assay, and human PPARalpha, PPARi, and PPARdelta assays. SRC-1 (676-700), biotinylated contains a covalently bonded N-terminal biotin tag that can be used for detection and purification.