Anti-PAS domain containing 1 antibodies enable researchers to detect and measure the PAS domain containing 1 antigen in biological samples. This target is a reported synonym of the PASD1 gene, which encodes PAS domain containing repressor 1. This protein is known to function in the regulation of transcription, among other biological roles. The human version of PAS domain containing 1 has a canonical amino acid length of 773 residues and a protein mass of 87.4 kilodaltons, although 2 isoforms have been identified. It is reported to be localized in the nucleus of cells and notably expressed in the testis. Other names for this target antigen include circadian clock protein PASD1 and PAS domain containing 1.