Rat IgG2a Isotype Control Antibody

Background of Rat IgG2a Isotype Control Antibody (rtIgG2a Isotype Control)

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 IgG1 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 IgG2a isotype control and mutants (natural and engineered rtIgG2a isotype controls) are useful for functional study using animal model among a number of in vitro and in vivo research applications including ELISA, Western Blot (WB), Flow Cytometry (Flow), Immunoprecipitation (IP), Immunohistochemistry (Paraffin) (IHC (P)), and Immunohistochemistry (Frozen) (IHC (F)). Rat IgG2a and IgG1 antibodies are more like mouse IgG1 than rat IgG2b antibodies. Most of rat antibodies are used to study mouse and human target proteins.

Please contact us to ask for a quote for the engineered rat IgG2a isotype control mutants, rtIgG2a isotype control and mutants with Avi-, His-, and DYKDDDDK-tags, and biotinylated rtIgG2a isotype control and mutants. A variety of conjugates (such as dyes and fluorophores) with the rat IgG2a isotype control and Fc mutants are available.

PA007143: In Vivo Grade Recombinant Rat IgG2a Isotype Control Antibody (rtIgG2a Isotype Control)

The in vivo grade recombinant rat IgG2a isotype control antibody (rtIgG2a isotype control) was produced in HEK 293 cells.
Immunogen: N/A.
Clone: 12B9.
Isotype: rat IgG2a, kappa.
Applications: an isotype-matched negative control for rat IgG2a kappa antibodies used in ELISA, Western Blot (WB), Flow Cytometry (Flow), Immunoprecipitation (IP), Immunohistochemistry (Paraffin) (IHC (P)), Immunohistochemistry (Frozen) (IHC (F)), and in vivo animal model research.
Formulation: 0.2 μM filtered solution of 1x PBS.
Purity: >95% by SDS-PAGE under reducing conditions.
Endotoxin Level: Less than 1 EU/mg of protein as determined by LAL method.

Shipping: The recombinant rtIgG2a isotype control is shipped with ice pack. Upon receipt, store it immediately at the temperature recommended below.

Stability & Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
1 month from date of receipt, 2 to 8°C as supplied.
3 months from date of receipt, -20°C to -70°C as supplied.

References of Rat IgG2a Isotype Control Antibody:

TIGIT predominantly regulates the immune response via regulatory T cells.
Kurtulus, S., et al. J Clin Invest. 2015 Nov;125(11):4053-62. doi: 10.1172/JCI81187. PMID: 26413872.
In some experiments, mice were treated with 250 μg isotype (rat IgG2a) or anti–TIM-3 Abs on the days indicated in the legend for Figure 7. ...A recent study suggests that TIGIT regulates T cell function by inhibiting CD226 dimerization and downstream signaling. ...Upregulation of these receptors on effector T cells terminates T cell responses, while their expression on Tregs promotes their suppressor function. ...T cell Ig and ITIM domain (TIGIT) is a recently identified coinhibitory receptor that is found on the surface of a variety of lymphoid cells, and its role in immune regulation is just beginning to be elucidated. ...We demonstrated that TIGIT signaling in Tregs directs their phenotype and that TIGIT primarily suppresses antitumor immunity via Tregs and not CD8+ T cells. Moreover, TIGIT+ Tregs upregulated expression of the coinhibitory receptor TIM-3 in tumor tissue, and TIM-3 and TIGIT synergized to suppress antitumor immune responses.
Tags: activity of Rat IgG2a Isotype Control; activity of Rat IgG2a Isotype Control mAb

Animal model of respiratory syncytial virus: CD8+ T cells cause a cytokine storm that is chemically tractable by sphingosine-1-phosphate 1 receptor agonist therapy.
Walsh, K. B., et al. J Virol. 2014 Jun;88(11):6281-93. doi: 10.1128/JVI.00464-14. PMID: 24672024.
For cell depletion experiments, 250 μg of anti-NK1.1 and/or 500 μg of anti-CD8 antibodies were administered i.p. to mice 1 day before and 1 day after infection. Rat IgG2a was administered at equivalent concentrations for isotype control-treated mice within the cell depletion experiments. ...The cytokine storm is an intensified, dysregulated, tissue-injurious inflammatory response driven by cytokine and immune cell components. ...Now we describe a novel event where virus-specific T cells induce a cytokine storm. ...The paramyxovirus pneumonia virus of mice (PVM) is a model of human respiratory syncytial virus (hRSV). ...Blockading these cytokines with neutralizing antibodies blunts the cytokine storm and protects the host.
Tags: Rat IgG2a Isotype Control antibody; human IgG1 recombinant isotype control

The oestrous cycle stage affects mammary tumour sensitivity to chemotherapy.
Bornes, L., et al. Nature. 2025 Jan;637(8044):195-204. doi: 10.1038/s41586-024-08276-1. PMID: 39633046.
Individual mice were treated every week with either 60 mg kg−1 of either InVivoMAb anti-mouse CSF1R (CD115) monoclonal antibody or InVivoMAb rat IgG2a isotype control (BioXCell, clone 2A3, catalogue no. BE0089), or received InVivoMAb anti-mouse CD4 and InVivoMAb anti-mouse CD8 three times per week, every other day, with a first dose of 400 µg followed by 200 µg per antibody. ...The response of breast cancer to neoadjuvant chemotherapy (NAC) varies substantially, even when tumours belong to the same molecular or histological subtype. ...In three mouse models of breast cancer, we show reduced responses to NAC when treatment is initiated during the dioestrus stage, when compared with initiation during the oestrus stage. ...Similar findings were observed in retrospective premenopausal cohorts of human patients. ...Whereas NAC disrupts the oestrous cycle, this elevated macrophage prevalence persists and depletion of macrophages mitigates the reduced therapy response observed when initiating treatment during dioestrus.
Tags: Rat IgG2a Isotype Control antibody for cancer research; Rat IgG2a Isotype Control antibody for mouse tumor model

Chimeric antigen receptor macrophages (CAR-M) sensitize HER2+ solid tumors to PD1 blockade in pre-clinical models.
Pierini, S., et al. Nat Commun. 2025 Jan 15;16(1):706. doi: 10.1038/s41467-024-55770-1. PMID: 39814734.
In designated experiments, 10 µg/mL of InVivoMAb anti-mouse PD-1 or 10 µg/mL InVivoMAb rat IgG2a isotype control (BE0089, Bio X Cell) was added to the wells. ...We previously developed human CAR macrophages (CAR-M) and demonstrated redirection of macrophage anti-tumor function leading to tumor control in immunodeficient xenograft models. ...In vivo, anti-HER2 CAR-M significantly reduce tumor burden, prolong survival, remodel the TME, increase intratumoral T cell and natural killer (NK) cell infiltration, and induce antigen spreading. ...CAR-M therapy protects against antigen-negative relapses in a T cell dependent fashion, confirming long-term anti-tumor immunity. ...These results demonstrate synergy between CAR-M and T cell checkpoint blockade and provide a strategy to potentially enhance response to aPD1 therapy for patients with non-responsive tumors.
Tags: Rat IgG2a Isotype Control for animal model; Rat IgG2a Isotype Control for cancer research

Tamm-Horsfall protein augments neutrophil NETosis during urinary tract infection.
Mercado-Evans, V., et al. JCI Insight. 2025 Jan 9;10(1):e180024. doi: 10.1172/jci.insight.180024. PMID: 39589812.
Serial dilutions of homogenates and urine were plated on LB agar to enumerate CFU. For neutrophil depletion, mice injected i.p. with 10 μg of anti-Ly6G or rat IgG2a isotype in 100 μL prior to infection. ...Urinary neutrophils are a hallmark of urinary tract infection (UTI), yet the mechanisms governing their activation, function, and efficacy in controlling infection remain incompletely understood. ...Tamm-Horsfall glycoprotein (THP), the most abundant protein in urine, uses terminal sialic acids to bind an inhibitory receptor and dampen neutrophil inflammatory responses. ...In a UTI model, THP-deficient mice showed elevated urinary tract bacterial burdens, increased neutrophil recruitment, and more severe tissue histopathological changes compared with WT mice. ...These effects were observed only in the presence of a NETosis stimulus and could not be solely replicated with equivalent levels of sialic acid alone.
Tags: function of Rat IgG2a Isotype Control antibody; bulk Rat IgG2a Isotype Control

For more references about Rat IgG2a Isotype Control Antibody please contact our scientific support team with message@sydlabs.com.

Questions and Answers:

Question: Why do you use mouse variable regions in your recombinant rat IgG isotype controls?
Answer: Most in vivo functional grade rat IgG antibodies are used to study mouse target proteins. An ideal isotype control matches the isotype of the primary antibody used in the application but lacks binding to the target. It is normally used as a negative control to differentiate any non-specific background signal from the specific antibody signal. The use of mouse variable regions can reduce the potential immunogenicity induced by the rat variable regions in the rat IgG isotype controls from the rat hybridoma cell lines.

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 IgG2a isotype control (catalog # PA007143) 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)