Transcription factors contain both a DNA-binding and a trans-activating domain which allow binding to specific DNA sequences and subsequent regulation of nearby genes. The transcription factor may then upregulate or activate genes by stabilizing the binding of RNA polymerase or causing the acetylation of histones. Conversely, blocking RNA polymerase or causes downregulation or transcriptional repression. The human genome encodes an abundance of transcription factor genes; they comprise 10% of all genes, of which there are many subclasses. ELISA kits for your transcription factor of interest may be available from a number of suppliers. Enter the target name or select filters to help simplify your search.