Ready-to-use ELISA kits are available for the detection of ribonucleotide reductase M1, an alias of the protein, ribonucleotide reductase catalytic subunit M1. The official gene symbol is RRM1. The protein, with a mass of 90.1 kDa and length of 792 residues, is reported to be cytoplasmic. It is a member of the Ribonucleoside diphosphate reductase large chain family and may be known by other names, including: RR1, ribonucleotide reductase R1 subunit, ribonucleotide reductase M1 polypeptide, ribonucleoside-diphosphate reductase subunit M1, and ribonucleoside-diphosphate reductase large subunit.