How to find the right Lab Antigens AI guide

What the AI looks for in Lab Antigens

Exact antigen identity

Match the species, protein, isoform or strain, and the region covered (full-length, ectodomain or fragment) to the gene accession and amino-acid range on the datasheet. An antibody or assay raised against one domain or species often fails on another, and fragments can lack the epitope you need.

Expression system

Choose mammalian-expressed (HEK293, CHO) or native antigen when glycosylation or conformation matters. E. coli-expressed is fine for linear epitopes and Western blot. Bacterially expressed proteins are unglycosylated and may misfold, which changes antibody binding in ELISA and in functional assays.

Purity

Look for stated SDS-PAGE purity, commonly at least 90 to 95 percent, backed by a lot-specific certificate of analysis. Contaminating host proteins cause false positives in serology and immunization work.

Endotoxin level

For cell culture, immunization or in vivo use, require a stated low-endotoxin specification measured by LAL assay. Endotoxin triggers immune activation that confounds cell and animal experiments.

Tag and its position

Check which tag is used (His, Fc, Avi or none) and whether it sits at the N- or C-terminus. For capture assays, pick a tag that does not compete with your detection reagents. Fc tags bind anti-Fc secondaries, and terminal tags can mask epitopes near that end.

Format and storage

Lyophilized antigens need the stated reconstitution buffer. Aliquot after reconstitution and avoid repeated freeze-thaw cycles. Improper reconstitution and freeze-thaw cycles cause aggregation and loss of activity.