About Us

Nebulabio is a premier contract service organization specializing in high-precision antibody purification and process development. We provide end-to-end solutions for researchers, diagnostic developers, and biotech companies, transforming raw samples—whether from hybridoma culture, mammalian expression systems, or antisera—into pure, active, and application-ready antibody preparations. Our expertise lies in designing and executing robust purification strategies that maximize yield, purity, and functionality while ensuring biological activity is preserved. From small-scale research-grade purification to larger-scale preclinical and diagnostic reagent production, we combine scientific rigor with state-of-the-art chromatographic systems to deliver consistent, reliable results. Our mission is to be your trusted partner in downstream processing, saving you time and resources while guaranteeing the quality essential for sensitive assays, therapeutic candidate screening, and diagnostic manufacturing.

☞Classification and Comparison of Antibody Purification Methods

Selecting the optimal purification strategy is critical and depends on the antibody source, isotype, desired purity, and final application. We offer a full spectrum of chromatographic techniques.

①Affinity Chromatography:

• Protein A/G/L Resins: The gold standard for purifying most IgG antibodies directly from complex mixtures. Protein A has high affinity for human, rabbit, and mouse IgG (particularly Fc region). Protein G offers broader binding, especially for rat, goat, sheep IgG and mouse IgG1. Protein L binds to the light chain, ideal for antibody fragments (scFv, Fab) lacking an Fc region.

• Antigen-Based Affinity: For ultimate specificity, especially for polyclonal antibodies, we can couple the target antigen to a resin for highly specific purification.

• Best for: Primary capture step, achieving >95% purity in one step from culture supernatant or serum.

②Ion Exchange Chromatography (IEX):

• Cation Exchange (CEX): Most commonly used for antibodies at a pH below their isoelectric point (pI). Binds positively charged antibodies.

• Anion Exchange (AEX): Often used in flow-through mode as a polishing step to remove negatively charged impurities (host cell proteins, DNA, endotoxins).

• Best for: Polishing step after affinity capture, removing aggregates, charge variants, and residual impurities.

③Hydrophobic Interaction Chromatography (HIC):

• Separates molecules based on surface hydrophobicity under high salt conditions.

• Best for: Excellent for removing antibody aggregates and fragments, as aggregates often have more exposed hydrophobic regions.

④Multimodal or Mixed-Mode Chromatography:

• Resins combining two or more interaction modes (e.g., hydrophobic and ionic).

• Best for: Challishing polishing steps, offering unique selectivity for difficult separations.

⑥Size-Exclusion Chromatography (SEC or Gel Filtration):

• Separates molecules based on size. Does not bind the antibody.

• Best for: Final polishing step for buffer exchange, removal of small-molecule contaminants, and separation of monomers from aggregates and fragments.

☞Antibody Purification Process

Our standard purification cascade is a multi-step approach designed for maximum purity and recovery:

①Clarification & Capture: The crude sample (cell culture supernatant, ascites fluid, or antiserum) is clarified via depth filtration or centrifugation to remove cells and debris. The clarified fluid is then loaded onto an affinity column (Protein A/G). The antibody binds specifically, while the majority of impurities flow through.

②Elution & Viral Inactivation (if required): The bound antibody is eluted, typically using a low-pH buffer. This low-pH hold step also serves as a common viral inactivation method for therapeutic processes.

③Polishing: The eluted antibody is adjusted to appropriate conditions (pH, conductivity) for the next step. One or two polishing steps are employed:

• Ion Exchange Chromatography: Often CEX for bind-and-elute or AEX in flow-through mode.

• Hydrophobic Interaction Chromatography: To remove aggregates.

④Final Polishing & Formulation: The purified antibody undergoes a final Size-Exclusion Chromatography step to transfer it into the desired final formulation buffer (e.g., PBS) and ensure removal of any remaining aggregates.

⑤Concentration & Sterile Filtration: The pooled antibody fraction is concentrated to the target concentration using centrifugal concentrators and passed through a 0.22 µm filter for sterilization.

Figure1.Employing simple precipitation (fractionation) using Cohn method and weak anion exchange chromatography with DEAE resin, antibodies such as Immunoglobulin G are purified from human plasma. 

☞Nebulabio’s Service Process

• Step 1: Project Consultation & Sample Assessment. We discuss your antibody source, species, isotype, quantity, required purity, and intended use. We also assess your provided sample.

• Step 2: Process Design & Proposal. Based on the consultation, we design a customized purification strategy (e.g., Protein A → CEX → SEC) and provide a detailed project plan, timeline, and quote.

• Step 3: Small-Scale Run & Optimization (Optional but Recommended). For critical projects or novel antibodies, we perform a small-scale test run to optimize conditions, confirm recovery, and generate preliminary QC data.

• Step 4: Scale-up & Full Batch Processing. Upon your approval, we execute the full purification process at the agreed scale.

• Step 5: Comprehensive Quality Control. Every purified batch undergoes mandatory QC: SDS-PAGE (reducing/non-reducing) for purity assessment, SEC-HPLC for aggregate quantification, Endotoxin testing (LAL assay), and concentration measurement (A280). Functional testing (ELISA, binding assay) can be added.

• Step 6: Final Delivery. You receive the purified antibody, a detailed Certificate of Analysis with all QC data, and a full process report.

☞Why Choose Us for Antibody Purification?

• Tailored Strategies, Not Just Kits: We don’t offer one-size-fits-all kits. Every protocol is customized based on your antibody’s unique properties and your final application requirements.

• Expertise in Challenging Antibodies: We successfully purify difficult antibodies, including IgM, IgA, engineered fragments (scFv, Fab, nanobodies), and low-stability antibodies, requiring specialized resin selection and gentle handling.

• Process Development & Scale-up Capability: We seamlessly bridge from small-scale (mg) for research to larger-scale (100s of mg to grams) for preclinical and diagnostic manufacturing, ensuring process consistency.

• Rigorous, Transparent QC: We provide extensive, trustworthy data with every batch. You know exactly what you are getting—purity level, aggregate content, endotoxin levels—enabling confidence in your downstream experiments.

• Focus on Activity Preservation: Our processes are optimized not just for purity and yield, but for maintaining the biological activity and native conformation of your antibody.

• Efficiency & Time Savings: Outsourcing to our experts with dedicated equipment and optimized protocols frees your lab from the time-consuming and often tricky process of purification, accelerating your project timeline.

☞Partner with Nebulabio

Leverage our expertise and dedicated technology platform to transform your antibody purification challenges into reliable, high-quality results. We are committed to becoming an extension of your team, providing the scientific rigor and precision necessary to advance your research, diagnostic, or therapeutic programs. Whether you require research-grade purity for critical assays or consistent, scalable processes for reagent production, we deliver the confidence and performance you need.