Antigen standard for zinc finger and SCAN domain containing 21 (ZSCAN21) is a lysate prepared from HEK293T cells transiently transfected with a TrueORF gene-carrying pCMV plasmid (OriGene Technologies, Inc.) and then lysed in RIPA Buffer. Protein concentration was determined using a colorimetric assay. The antigen control carries a C-terminal Myc/DDK tag for detection.