Mouse IgG, Rabbit IgG, Sheep IgG

There are five classes of immunoglobulins, which are defined by their heavy chain type: Cγ for IgG; Cμ for IgM; Cα for IgA; Cε for IgE, and Cδ for IgD. rabbit immunoglobulins have been found to be of class IV (without IgD). Immunoglobulin G (IgG antibodies) play a role in the immune response by activating the complement and neutralizing a variety of toxins. IgG antibody are long lasting and are the only antibodies that cross the placenta to protect the fetus during the mother's pregnancy. They are also secreted from the mammary glands into the colostrum, so that the newborn is protected by antibodies in the first instance. IgG is a four-chained monomer, accounting for 75% of the total amount of serum Ig, and it is the most important antibody component in serum and extracellular fluid.

The most abundant immunoglobulin in rabbit serum is IgG, with a serum concentration of 5-20 mg/ml. it is different from IgG in other animals. Rabbits have only one IgG subtype, whereas mice have IgG1, IgG2a, IgG2b, IgG2c and IgG3 subtypes, and rats have IgG1, IgG2a, IgG2b and IgG2c subtypes. Rabbit IgG tends to have fewer amino acids in the N-terminal and D-E loops and additional disulfide bonds in the variable regions of the heavy chain compared to mouse and human IgG, which may account for making rabbit monoclonal antibodies more stable. It is this simpler structure and more stable nature of rabbit IgG that makes it easier to clone molecules that are key antibodies in antibody drug development, and makes the results of various applications in the laboratory more stable.

KMD Bioscience is a company dedicated to providing high-quality biologically active raw materials such as antigens, antibodies, enzymes and substrates, and related technical services. KMD Bioscience has a series of technical platforms for protein recombination, antibody production, purification and diagnostic reagent R&D and production (including immunochromatography, enzyme immunoassay and chemiluminescence); and a group of highly qualified in vitro diagnostic upstream and downstream technicians with rich experience, which provide guarantee for the company's research and development, and production of high-quality raw materials for in vitro diagnostic reagents and related technologies.

The inventory of reagents associated with immunoglobulin that KMD Bioscience can offer:

Difference between rabbit IgG and mouse IgG

Rabbit Antibody Molecular Weight Different types and subtypes of antibodies have different molecular weights. The common rabbit IgG type has a molecular weight of 150 KD under non-reducing conditions, and contains two heavy chains (about 50 KD each) and two light chains (about 25 KD each). Under reducing conditions, the molecular weights of the heavy and light chains are 50 and 25 kD, respectively.

The heavy chains of murine IgG all have a stable region consisting of three immunoglobulin structural domains, the IgG1 stable region has 324 amino acids, the heavy chains contain approximately 450 amino acids, and each light chain (kappa or lambda) contains a stable immunoglobulin structural domain and a variable immunoglobulin structural domain with a length of approximately 211 to 217 amino acids. Typical molecular weight of IgG is about 150 KD. In the reduced form, each heavy chain is about 50 KD and each light chain is about 25 KD.

Sheep immunoglobulin (ovine immunoglobulin), IgG can be divided into IgG1, IgG2 and IgG3. IgG antibody subtype is the most abundant serum immunoglobulin subtype in the immune system. Sheep IGG is secreted by B-cells and is present in blood and extracellular fluids to protect against infections caused by bacteria, fungi and viruses.

Figure 1 Schematic structure of natural rabbit IgG

Figure 2 Schematic structure of mouse IgG

Advantages of rabbit IgG

First of all, in taxonomy, rabbits belong to the order Lagomorpha, which is more distant in evolutionary relationship from the order Rodentia, to which rats and mice belong. Rabbit antibodies recognize epitopes in human antigens that are not recognized by murine monoclonal antibodies, significantly increasing the number of epitopes that can be used and facilitating the development of antibodies against both human and murine homologous proteins. Secondly, rabbits show a significant immune response to small molecules and hemi antigens (haptens), whereas in rodents there is no significant immune response. Third, the vast majority of mouse strains in use today are inbred, whereas there is a dearth of inbred strains in rabbits. Inbred strains result in a significant reduction in the diversity of immune responses. Immunohistochemistry (IHC) of mouse and rabbit monoclonal antibodies against the same human antigens has shown that rabbit monoclonal antibodies consistently exhibit greater sensitivity than mouse monoclonal antibodies. Fourth, the common monoclonal antibody production techniques nowadays require the collection of B cells from spleen, bone marrow or blood. Rabbits are significantly larger than mice, so the number of B cells obtained from a single animal is higher. Fifth, the genetic mechanisms of antibody production and diversification in rabbits are significantly different from those in humans and mice. The individual development of rabbit B cells and antibody pools is characterized by three main distinct developmental stages of B cells. Sixth, the simplicity of rabbit IgG makes it easy to molecularly clone, engineer and humanize antibodies, which is critical in antibody drug development.

KMD Bioscience offers a variety of diagnostic components for infectious diseases, tumors, inflammation, nail function, hormones, and other areas.

KMD Bioscience can provide a wide range of bioactive materials and technical services for IVD, which are widely used by domestic and foreign manufacturers of related reagents. These include, but are not limited to, customized development of antigens and antibodies, antigen-antibody labeling and coupling, antibody pair screening and purification, immunochromatography, enzyme immunoassay and chemiluminescence system optimization and process debugging, and many other technologies.