T7 Tag Peptide

Recombinant antibody expression produces antibody chains from cloned antibody genes in mammalian cells, commonly HEK293-derived cells, so that secreted IgG or Fc-fusion antibodies can be collected from culture supernatant. Protein A/G purification is affinity chromatography in which immobilized Protein A, Protein G, or Protein A/G binds the antibody Fc region; nonbound culture components are washed away, and bound antibody is recovered by changing buffer conditions, commonly acidic elution followed by neutralization.

Recombinant protein expression in Escherichia coli followed by purification of a His-tagged soluble protein by immobilized metal affinity chromatography (IMAC), with optional MBP fusion and TEV tag removal when the construct includes these elements. The biological readout is production of the encoded target protein, detected as an inducible band at the expected molecular mass by SDS-PAGE and quantified by total protein assay or chromatographic absorbance; the purification readout is enrichment of the target protein in elution fractions after selective binding of polyhistidine residues to immobilized Ni2+/metal-chelate resin and elution by imidazole-containing buffer. Expression is driven by an inducible bacterial expression system, commonly T7/lac-based, in which IPTG or lactose/auto-induction activates transcription and translation of the cloned gene; lower induction temperature, lower inducer concentration, induction timing, and solubility-enhancing fusion tags can influence the frac