SeamlessBio — FBS Ultra Low IgG · Animal Sera · BSA · mAb Production
Hybridoma Culture & Monoclonal Antibody Production — Serum Selection Guide
Hybridoma technology remains the foundation of monoclonal antibody discovery. Four of the ten best-selling antibody drugs originate from hybridoma-based programmes. Every hybridoma lab requires serum — and the grade used directly determines fusion efficiency, clone detection sensitivity, and antibody purity. This guide covers the complete workflow from immunisation to formulation.
Why FBS Ultra Low IgG is the correct grade for hybridoma culture:
Standard FBS contains 200–800 µg/mL bovine IgG. In hybridoma supernatant screening, bovine IgG creates high background signal in ELISA — masking low-titre clones. In downstream purification, bovine IgG co-purifies with the target mAb on Protein A/G columns, reducing purity. FBS Ultra Low IgG <5 µg/mL eliminates both problems at source.
Hybridoma Workflow — Serum at Each Stage
| Stage | Process Step | Recommended Product | Key Note |
|---|---|---|---|
| Immunisation | Host animal immunisation (mouse, rat, rabbit, goat) | Species-matched pre-immune serum as negative ELISA control: Mouse | Rat | Rabbit | Goat Serum |
Pre-immune serum required as negative control for titre monitoring throughout the immunisation programme |
| Fusion | B cell / myeloma cell fusion — PEG or electrofusion | FBS Ultra Low IgG <5 µg/mL — 10–20% in HAT medium | Low IgG reduces ELISA background in post-fusion screening. HAT medium requires high-quality serum for hypoxanthine/thymidine uptake efficiency. |
| HAT Selection | Selective culture of hybridoma clones in HAT medium | FBS Ultra Low IgG <5 µg/mL — 10–20% | Consistent lot quality critical — HAT selection efficiency varies with FBS lot. Batch reservation strongly recommended. |
| Screening | ELISA screening of hybridoma supernatants | FBS Ultra Low IgG <5 µg/mL + BSA Low Endotoxin for ELISA blocking | Bovine IgG creates ELISA background that masks low-titre positive clones. BSA Low Endotoxin at 1–3% in PBS-Tween as blocking agent. |
| Cloning | Limited dilution or FACS single-cell sorting | FBS Ultra Low IgG <5 µg/mL — 20% for single-cell recovery | Higher serum supports single-cell recovery. Feeder cells (peritoneal macrophages) — species-matched serum recommended. |
| Expansion | Scale-up of positive clones | FBS Ultra Low IgG <5 µg/mL — 5–10% | Reduce serum at expansion to lower bovine IgG load in supernatant before purification. |
| Production | Antibody production — static flasks, roller bottles, bioreactor | FBS Ultra Low IgG <5 µg/mL — 2–5% or serum-free | Minimise serum at production — less bovine IgG co-purification on Protein A/G. Serum-free preferred for GMP-grade mAb. |
| Purification | Protein A/G, buffer exchange, formulation | BSA Low Endotoxin ≤5 EU/mg in formulation buffer | BSA at 0.001–0.1% prevents mAb adsorption to vial surfaces. Low Endotoxin grade essential. |
Standard FBS vs FBS Ultra Low IgG — What Difference It Makes
| Parameter | Standard FBS | FBS Ultra Low IgG <5 µg/mL |
|---|---|---|
| Bovine IgG content | 200–800 µg/mL | <5 µg/mL — chromatographically depleted |
| ELISA screening background | High — bovine IgG cross-reacts with anti-mouse/rabbit secondary antibodies | Minimal — background eliminated |
| Protein A/G purification | Bovine IgG co-purifies — reduces mAb purity | No bovine IgG co-purification |
| Clone detection sensitivity | Low-titre clones masked by background | Full detection sensitivity — no masking |
| Growth factors / albumin | Standard levels | Fully retained — depletion is IgG-specific only |
Animal Sera for Immunisation — Pre-Immune Controls
Species-matched serum is required as a negative control at each stage of the immunisation programme — pre-immune baseline, mid-programme titre checks, terminal bleed comparison. SeamlessBio supplies sera from all common laboratory animal species.
| Species | Application in mAb Programme | Product |
|---|---|---|
| Mouse (BALB/c) | Most common hybridoma host — pre-immune serum for ELISA baseline. Normal mouse serum as negative control throughout. | Mouse Serum → |
| Rat | Rat hybridoma programmes. Rat anti-mouse antibody production. | Rat Serum → |
| Rabbit | High-affinity antibody programmes. B cell immortalisation. Pre-immune control. | Rabbit Serum → |
| Goat | Polyclonal antibody production. Pre-immune goat serum as ELISA blocking agent for goat-derived secondary antibodies. | Goat Serum → |
| Sheep | Sheep polyclonal programmes. Normal sheep serum as blocking agent. | Sheep Serum → |
| Guinea Pig | Complement source in CDC and complement fixation assays. Highly potent complement activity. | Guinea Pig Serum → |
BSA in Antibody Production — Key Applications
| Application | BSA Grade | Concentration | Function |
|---|---|---|---|
| ELISA blocking buffer | BSA Low Endotoxin ≤5 EU/mg | 1–3% in PBS-T | Blocks non-specific binding — low endotoxin critical to avoid cell activation during blocking |
| Antibody dilution buffer | BSA Low Endotoxin | 0.1–1% | Stabilises antibody during serial dilution — prevents adsorption to tube surfaces |
| Conjugation buffer (HRP, biotin, fluorophore) | BSA Fatty Acid-Free | 0.1% | Protein stabiliser during conjugation reactions — fatty acid-free eliminates lipid interference |
| Formulation buffer | BSA Low Endotoxin | 0.001–0.1% | Prevents mAb adsorption to vial surfaces during low-concentration antibody storage |
Human Serum AB for Human Hybridoma & EBV Immortalisation
For human mAb programmes using EBV immortalisation of human B cells or human hybridoma technology, human serum is required — not FBS. Human B cells require a species-matched matrix.
| Application | Product | Why |
|---|---|---|
| EBV-immortalised human B cell culture | Human Serum AB Heat Inactivated — 10% | HI eliminates complement-mediated lysis of EBV-immortalised B cells. AB type prevents blood group agglutination. |
| Human hybridoma culture | Human Serum AB HI — 10–20% | Species-matched matrix for human × human hybridoma products. Eliminates xenogenic stimulation from bovine components. |
Frequently Asked Questions
Why is FBS Ultra Low IgG required for hybridoma culture?
Standard FBS contains 200–800 µg/mL bovine IgG. When hybridoma supernatants are screened by ELISA with anti-mouse or anti-rabbit secondary antibodies, the secondary cross-reacts with bovine IgG — creating background that masks low-titre positive clones. Additionally, bovine IgG co-purifies with the target mAb on Protein A/G columns, reducing final purity. FBS Ultra Low IgG <5 µg/mL eliminates both problems at source.
What BSA grade for ELISA blocking in hybridoma screening?
BSA Low Endotoxin ≤5 EU/mg is the correct grade. High-endotoxin BSA activates cells during blocking incubation and generates non-specific ELISA signal. For maximum assay sensitivity in hybridoma screening ELISAs, BSA Low Endotoxin at 1–3% in PBS-Tween blocking buffer is the standard approach.
Can I use standard FBS for the immunisation stage?
The immunisation stage does not involve cell culture — it is an in vivo process. FBS is not used for immunisation. What is required is species-matched pre-immune serum from the host animal as a negative ELISA control for titre monitoring throughout the immunisation programme.
Which serum for guinea pig complement in CDC assays?
Normal Guinea Pig Serum is the standard complement source for CDC and complement fixation assays. Guinea pig complement is highly active and broadly reactive — the conventional choice for CDC assays in hybridoma-derived anti-tumour mAb characterisation.
Request Free Test Volumes
FBS Ultra Low IgG, animal sera, and BSA Low Endotoxin samples available. Lot-specific IgG data. Batch reservation for extended hybridoma programmes.
Email: info@seamlessbio.de | +49 851 37932226
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