Description

Protein G is a highly purified bacterial cell wall protein derived from group G streptococci, renowned for its exceptional affinity for the Fc region of a broad range of immunoglobulin G (IgG) subclasses from various species. This makes it an indispensable tool for antibody purification, immunoprecipitation, and immunoassay development in life science research and biopharmaceutical manufacturing. It is critical for researchers and production facilities requiring high-purity antibody isolation and detection, particularly in the development of monoclonal antibody therapeutics, diagnostic kits, and vaccine production.

Application

• Antibody Purification: Immobilized on chromatographic resins (e.g., agarose, magnetic beads) for the affinity purification of polyclonal and monoclonal IgG antibodies from serum, ascites fluid, or cell culture supernatants.
• Immunoprecipitation (IP) & Co-Immunoprecipitation (Co-IP): Used to isolate specific antigen-antibody complexes from complex biological samples for downstream analysis like western blotting or mass spectrometry.
• Immunoassay Development: Conjugated to enzymes, fluorophores, or other labels for use in ELISA, lateral flow assays, and other diagnostic platforms to capture and detect antibodies.
• Cell Surface Staining & Flow Cytometry: Fluorescently labeled Protein G is used as a secondary detection reagent for antibodies bound to cell surface antigens.
• Microarray and Biosensor Coating: Immobilized on chips or sensor surfaces to create antibody-capture platforms for high-throughput screening and biomarker discovery.
• Therapeutic Antibody Production: Integral in downstream processing during the manufacturing of monoclonal antibody (mAb) drugs to ensure product purity and consistency.

Basic Information

Product Name	Protein G
CAS No.	90698-81-0
Molecular Formula	Contact for details
Molecular Weight	~22-25 kDa (Recombinant, varies by construct)
Synonyms	Streptococcal Protein G; Immunoglobulin G-binding Protein G; IgG Fc-binding Protein; Recombinant Protein G; rProtein G; G Protein; Peroxidase-Conjugated Protein G; Biotinylated Protein G; Streptococcal Protein G, Recombinant; Fc Receptor Protein G
EINECS	Contact for details

Quality Control

Our Protein G is produced under stringent conditions to ensure batch-to-batch consistency and high biological activity. Each lot undergoes rigorous quality testing, including purity assessment by SDS-PAGE and HPLC, functional activity testing via IgG binding capacity, and endotoxin level analysis. Certificates of Analysis (COA) detailing all specifications are available upon request to support your quality assurance and regulatory documentation needs.

Storage

Preserve in a tightly closed container, protected from light. For long-term stability, store lyophilized powder at 2-8°C. Reconstituted solutions should be aliquoted and stored at -20°C or below to prevent repeated freeze-thaw cycles. The product is hygroscopic (moisture-sensitive); ensure the container is sealed tightly after each use in a low-humidity environment.

Specification

Item	Specification
Appearance	White or off-white lyophilized powder
Identification (IR)	Conforms to structure
Purity (SDS-PAGE)	≥ 95%
Assay (HPLC)	≥ 98%
Protein Content (Biuret)	≥ 90%
IgG Binding Capacity	≥ 20 mg human IgG/ml settled gel
Endotoxin (LAL)	< 10 EU/mg
Solubility	Soluble in water or PBS, pH 7.4

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.