Rat IgG1 Isotype Control Antibody

Background:
Rat IgG antibodies are classified to four subclasses mainly based on the isotype of the heavy chain (IgG1, IgG2a, IgG2b, and IgG2c for the heavy chain; kappa and lamda for the light chain), of which IgG2b and IgG2a, and kappa are the most abundantnamed in serum. IgG antibodies are large molecules of about 150 kDa composed of four peptide chains, two identical heavy chains of about 50 kDa and two identical light chains of about 25 kDa. The four peptides are arranged in a Y-shape tetramer by disulfide bonds formed between the two heavy chains and between a heavy chain and a light chain. Rat IgG1 antibodies can be purified by the protein G beads, and relatively lower yield by the protein A beads. Questions and Answers: Question: Why do you use mouse variable regions in your recombinant rat IgG isotype controls? Answer: The isotype control is normally used to differentiate any non-specific background signal from the specific antibody signal, including the immunogenicity if used in animals. Most in vivo functional grade rat IgG antibodies are used to study mouse target proteins. Many scientists use rat IgG isotype controls with rat antibody variable regions assuming that they induce the same immune response in mice, if there is any, as the rat antibodies of interest. However, two rat variable regions including the one in the rat IgG isotype control do not necessarily induce the same immune response in mice because in some cases, even one amino acid difference can make difference. Mouse variable regions can be used to show the potential immunogenicity induced by the rat variable regions in the rat IgG antibodies to test. Thus, it is better to use the mouse variable region in the rat IgG isotype control. Question: What is the advantage of the recombinant antibody production method compared to the hybridoma method? Answer: We use chemically defined medium for cell culturing to produce the recombinant rat IgG isotype controls. There is significant advantage for the in vitro method. First, we do not use mouse ascites for antibody production. Rat hybridoma cell lines usually adapt poorly to in vitro conditions, and generate ascites in immunocompromised mice rather than rats. Second, although antibodies can be produced by cell culturing from over 90% of hybridomas, there is a finite and significant failure rate. The recombinant method can be of help. Third, some companies and scientists add FBS into hybridoma cell culturing medium, which results in antibody contamination. There is no such contamination in production of recombinant antibodies. Fourth, we can easily switch the isotype with different antibody constant regions, and generate Fc mutations such as D265A which is used in therapeutic antibody research. It is better to use the same isotype control mutation. Question: Do you use the antibody sequences of MOPC21 (hybridoma clone number, isotype: mouse IgG1, kappa) or C1.18.4 (hybridoma clone number, isotype: mouse IgG2a, kappa) to develop your recombinant rat IgG isotype controls? Answer: Our recombinant rat IgG isotype controls including the rat IgG1 isotype control (catalog # PA007142) are not from MOPC21 nor C1.18.4 though we also produce and sell the MOPC21 and C1.18.4 rat IgG isotype controls. Please contact us and ask for MOPC21 and C1.18.4 derived recombinant rat IgG kappa isotype controls if you are interested. Other in vivo grade Recombinant IgG Isotype Control Antibodies and Mutants: In vivo Grade Recombinant Human IgG1 Isotype Control Antibody and Mutants In vivo Grade Recombinant Human IgG2 Isotype Control Antibody In vivo Grade Recombinant Human IgG3 Isotype Control Antibody In vivo Grade Recombinant Human IgG4-S228P Isotype Control Antibody and Mutants In vivo Grade Recombinant Mouse IgG1 Isotype Control Antibody and Mutants In vivo Grade Recombinant Mouse IgG2a Isotype Control Antibody and Mutants In vivo Grade Recombinant Mouse IgG2b Isotype Control Antibody and Mutants In vivo Grade Recombinant Mouse IgG2c Isotype Control Antibody and Mutants In vivo Grade Recombinant Mouse IgG3 Isotype Control Antibody In vivo Grade Recombinant Rat IgG1 Isotype Control Antibody In vivo Grade Recombinant Rat IgG2a Isotype Control Antibody In vivo Grade Recombinant Rat IgG2b Isotype Control Antibody In vivo Grade Recombinant Rat IgG2c Isotype Control Antibody In vivo Grade Recombinant Hamster IgG1 Isotype Control Antibody In vivo Grade Recombinant Hamster IgG2 Isotype Control Antibody In vivo Grade Recombinant IgG Fc Proteins: In vivo Grade Recombinant Human IgG1 Fc Protein (hIgG1) In vivo Grade Recombinant Human IgG2 Fc Protein (hIgG2) In vivo Grade Recombinant Human IgG4 Fc Protein (hIgG4) In vivo Grade Recombinant Mouse IgG1 Fc Protein (mIgG1) In vivo Grade Recombinant Mouse IgG2a Fc Protein (mIgG2a) In vivo Grade Recombinant Mouse IgG2b Fc Protein (mIgG2b) In vivo Grade Recombinant Rat IgG2a Fc Protein (rtIgG2a) In vivo Grade Recombinant Rat IgG2b Fc Protein (rtIgG2b) In vivo Grade Recombinant Llama IgG2b Fc Protein (lIgG2b) In vivo Grade Recombinant Rabbit IgG Fc Protein (rIgG)