Recombinant Antibody Expression & Production

Variable-region gene synthesis, vector construction, transient transfection, culture, purification and release testing — for monospecific and bispecific antibodies, on HEK293 and CHO expression systems.

From sequence to purified antibody, under one QC regime

Whether you start from a variable-region sequence or from a hybridoma clone, the route is the same: gene synthesis, vector construction, plasmid preparation, transient transfection, cell culture, purification and quality identification — with expressibility assessed before scale-up.

2.1 Monospecific

Monospecific antibody

Variable-region gene synthesis / vector construction + transfection / expression / purification.

2.2 Bispecific

Bispecific antibody

Variable-region gene synthesis / vector construction, whole-fragment gene synthesis / vector construction, transfection / expression / purification.

2.1

Monospecific antibody

Variable-region gene synthesis / vector construction + transfection / expression / purification.

Delivery quantity	Timeline	Typical application
≥ 1 mg	10–14 days	Activity screening, affinity evaluation, epitope analysis
≥ 10 mg	10–14 days	In vitro functional assays, cell-level activity confirmation
≥ 20 mg	10–14 days	Cell & in vitro efficacy evaluation, batch testing
≥ 50 mg	14–16 days	Mouse in vivo efficacy & pharmacokinetic pilot studies
≥ 100 mg	16–18 days	In vivo efficacy studies, preclinical preparation

Expression system: HEK293 / CHO.
Process: gene synthesis → vector construction → plasmid preparation → transient transfection → cell culture → purification and quality identification.
Acceptance criteria: SDS-PAGE (reduced) >90%, SEC-HPLC >90%, endotoxin <1 EU/mg.
Deliverables: expression plasmid, recombinant antibody and the Technical Report. Where the acceptance criteria are not met: the expression plasmid, all recombinant antibody already produced (if any), and the Technical Report.
Expressibility assessment: orders of 10 mg and above begin with an expressibility assessment (1 mg delivered).
Options: lyophilised aliquoting, secondary purification, constant-region engineering beyond the standard scope, and tighter endotoxin limits can all be arranged.

2.2

Bispecific antibody

Variable-region gene synthesis / vector construction — or whole-fragment gene synthesis / vector construction — followed by transfection / expression / purification.

Delivery quantity	Timeline	Typical application
≥ 0.2 mg	3–7 days	Expressibility assessment, activity screening
≥ 2 mg	3–7 days	In vitro binding & functional confirmation
≥ 4 mg	3–7 days	Cell-level efficacy evaluation
≥ 10 mg	6–10 days	Batch testing, in vivo pilot studies
≥ 20 mg	10–14 days	In vivo efficacy studies

Expression system: HEK293 / CHO.
Process: gene synthesis → vector construction → plasmid preparation → transient transfection → cell culture → purification and quality identification.
Acceptance criteria: SDS-PAGE (reduced) >90%, SEC-HPLC >90%, endotoxin <1 EU/mg.
Deliverables: expression plasmid, recombinant antibody and the Technical Report. Where the acceptance criteria are not met: the expression plasmid, all recombinant antibody already produced (if any), and the Technical Report.
Expressibility assessment: orders of 2 mg and above begin with an expressibility assessment (0.2 mg delivered).
Options: lyophilised aliquoting, secondary purification, constant-region engineering beyond the standard scope, and tighter endotoxin limits can all be arranged.

Gene synthesis timeline

Variable-region synthesis runs ahead of transfection; the timeline depends on fragment length.

Fragment length	Timeline
VH / VL < 400 bp	7 days
VH / VL > 400 bp	7–10 days

Workflow — recombinant antibody expression & purification

Seven documented stages from gene synthesis to release, 3–18 days depending on quantity.

Expression & purification

3–18 days

Gene synthesis

Variable region VH / VL

Vector construction

Expression vector assembly

Plasmid prep & QC

Confirmation before transfection

Transient transfection

HEK293 / CHO mammalian cells

Cell culture

Supernatant harvest

Affinity purification

Chromatographic capture

QC & release

Purity, SEC, endotoxin

Quality standard

Purity, monomer content and endotoxin are tested against defined acceptance criteria — and reported, not assumed.

Test item	Acceptance criterion	Method
Antibody purity (reduced)	> 90%	SDS-PAGE
Antibody monomer purity	> 90%	SEC-HPLC
Endotoxin	< 1 EU/mg	Limulus amoebocyte lysate (LAL)
Recombinant protein purity	> 90%	SDS-PAGE / SEC-HPLC
Supernatant antibody concentration	Quantitative report	Quantitative assay
Affinity	EC₅₀ determination	Concentration–binding curve fitting

Need a specific quantity, format or endotoxin limit?

Expression system, quantity, purification process, endotoxin limit and constant-region engineering are all adjustable. Tell us what you need and we will scope it.

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