There are a number of ELISA Kits available for the measurement of thymus cell antigen 1, theta, another term for the human protein, Thy-1 cell surface antigen. Other synonyms may include: thy-1 membrane glycoprotein, Thy-1 T-cell antigen, thy-1 antigen, and CD90. It is encoded by the THY1 gene to yield a protein 161 amino acids in length and 17.9 kDa in size. Versions of thymus cell antigen 1, theta are present in other organisms, including: Mouse, Rat, Frog.