Antibodies are glycoproteins secreted by specialized B lymphocytes that serve as the first response against infection. They comprise one of the main effectors of the adaptive immune system.
The high degree of affinity and specificity of antibodies towards antigens led to ubiquitous use of antibodies in life science and medical research. Antibodies can be monoclonal or polyclonal.
Monoclonal antibodies are produced by injecting an antigen into a host animal to initiate a humoral immune response. In most procedures, spleen cells from these hosts are fused in vitro with cultured malignant myeloma cells.
Unique cell clones are isolated and those that survive the fusion step are known as hybridomas. Hybridomas are immortal because of their myeloma characteristics and are easily propagated in culture.
Monoclonals are homologous to natural immunoglobulins from the source immunized animal, but unlike polyclonal antibodies purified from serum, they are specific to a single epitope and provide a stable long term supply of produced by hybridomas in vitro.
Invitrogen™ rabbit recombinant antibodies are derived from rabbit monoclonal antibody-producing cell lines by isolating and cloning the specific antibody heavy and light chain DNA sequences. These recombinant cloned antibodies are not susceptible to cell-line drift or lot-to-lot variation, thus allowing for peak specificity and performance.
ABfinity recombinant antibodies are highly specific and high-quality monoclonal antibodies, produced by proprietary technology, and unmatched for producing consistent results.
ABfinity antibodies are developed by immunizing animals, screening for functionality, and cloning the immunogen-specific antibody genes into high-level expression vectors.
The antibodies are produced on a large scale by expressing them in mammalian cells, and purifying them with protein A. These recombinant antibodies are expressed in mammalian expression systems, but appear just like their counterparts isolated from serum or produced by hybridomas.
Intact IgG appears on a non-reducing gel as ~150 kDa band and upon reduction generating a ~25 kDa light chain band and a ~50 kDa heavy chain.
The scheme below demonstrates how ABfinity monoclonal rabbit antibodies are produced.
ABfinity antibodies are manufactured by transfecting mammalian cells with heavy and light chain antibody cDNA. This highly reproducible process results in unparalleled lot-to-lot consistency. This consistency saves time and money because experimental conditions do not require revalidation.
Figure 1 below shows western blotting results achieved using independent lots of an ABfinity antibody, and its graphical representation.
Figure 2 shows the lot-to-lot consistency in immunocytochemistry, and its graphical representation.
The next figure shows the same results in flow cytometry.
Sensitivity and Specificity
The ABfinity antibodies only react with the target of choice, eliminating detection of the wrong signal due to unspecific binding. More highly sensitive antibodies can detect very low-level targets that may be difficult to detect with other antibodies. Plus, precious samples are saved, needing less antibody for detection.
Figure 4 shows a direct comparison of an ABfinity STAT4 antibody with the best commercial STAT4 antibodies in western blotting. This comparison includes antibodies from polyclonal, traditional hybridoma monoclonal, and rabbit hybridoma monoclonal platforms.
The next Figure demonstrates the same results in immunocytochemistry. Flow cytometry (results not shown) revealed similar results, indicating the sensitivity and specificity of ABfinity antibodies.
ABfinity antibodies are validated and characterized by multiple applications.
Examples of their application are shown in the following Figures.
Find out more about ABfinity antibodies on the Thermo Fisher website.