Anti-ALG9 alpha-1,2-mannosyltransferase antibodies are used for the immunodetection of the protein encoded by the ALG9 gene. In humans, the canonical protein has a reported length of 611 amino acid residues and a mass of 69.9 kDa. Its subcellular localization is in the ER. Alternative splicing is reported to yield 4 different isoforms for this protein. A member of the Glycosyltransferase 22 protein family, it is known to catalyze the transfer of mannose from Dol-P-Man to lipid-linked oligosaccharides. Post-translational modifications have been described, including glycosylation. The gene encoding this protein is implicated in Congenital disorder of glycosylation. Other names for this target antigen include asparagine-linked glycosylation 9 alpha-12-mannosyltransferase-like protein, asparagine-linked glycosylation 9 homolog (S. cerevisiae, alpha- 1,2-mannosyltransferase), and alpha-1,2-mannosyltransferase ALG9. Gene orthologs have been identified in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species.