Recombinant antibodies offer several key advantages compared to traditional antibodies. These include superior lot-to-lot consistency, continuous supply, and animal-free manufacturing. As such, recombinant antibodies are seeing increased use for scientific research, especially as a means of addressing the ongoing reproducibility crisis.
Traditional polyclonal and monoclonal antibodies are the product of normal B cell development and genetic recombination. They are generated by immunizing an animal with an antigen to elicit an immune response. While polyclonal antibodies are secreted by many different B cell clones and recognize multiple antigenic epitopes, monoclonals originate from a single B cell clone and are specific for just one epitope.
Recombinant antibodies are monoclonal, but their production involves in vitro genetic manipulation. After cloning the antibody genes into an expression vector, this is then transfected into an appropriate host cell line for antibody expression. Mammalian cell lines are most commonly used for recombinant antibody production, although cell lines of bacterial, yeast, or insect origin are also suitable.
Because recombinant antibody production involves sequencing the antibody light and heavy chains, it is a highly controlled and reliable process. In contrast, hybridoma-based systems for producing monoclonal antibodies are subject to genetic drift and instability, increasing the potential for lot-to-lot variability or loss of antibody expression. Recombinant antibodies are highly consistent from lot to lot, thereby ensuring reproducible experimental results.
In vitro methods for producing antibodies are amenable to large-scale production, meaning antibody availability is unlikely to become a limiting factor. Moreover, since the recombinant antibody sequence is known, continuity of supply is assured; in situations where an antibody will be used to support large, long-term studies, this can be an especially critical factor.
Unlike traditional methods for antibody production, recombinant approaches avoid the need to use animals. Where polyclonal antibodies are purified directly from the serum of the immunized host, and monoclonals are purified from either hybridoma-derived tissue culture supernatant or ascites, recombinant antibodies are instead purified from the tissue culture supernatants of transfected host cell lines. Regardless of whether an antibody is polyclonal, monoclonal or recombinant, it must always be properly validated in the intended application prior to experimental use. At CST, we adhere to the Hallmarks of Antibody Validation™, six complementary strategies for determining the specificity, sensitivity, and functionality of an antibody in any given assay. By carefully tailoring these strategies to each antibody product, we guarantee that CST antibodies will work as expected, to help you achieve results you can trust.
| Cat. # | Size | Qty. | Price |
|---|---|---|---|
| 36836S | 100 µl |
|
| REACTIVITY | All |
| SENSITIVITY | Transfected Only |
| MW (kDa) | |
| Source/Isotype | Rabbit IgG |
Product Information
| Application | Dilution |
|---|---|
| Immunofluorescence (Immunocytochemistry) | 1:200 |
| DNA Dot Blot | 1:1000 |
NOTE: Prepare solutions with reverse osmosis deionized (RODI) or equivalently purified water.
Blocking Buffer (1X PBS / 5% normal serum / 0.3% Triton™ X-100):
To prepare 10 ml, add 0.5 ml normal serum from the same species as the secondary antibody (e.g., Normal Goat Serum (#5425)) and 0.5 mL 20X PBS to 9.0 mL dH2O, mix well. While stirring, add 30 µl Triton™ X-100.
Recommended Fluorochrome-conjugated Anti-Rabbit secondary antibodies:
NOTE: Prepare solutions with reverse osmosis deionized (RODI) or equivalently purified water.
NOTE: All subsequent incubations should be carried out at room temperature unless otherwise noted in a humid light-tight box or covered dish/plate to prevent drying and fluorochrome fading.
posted December 2015
Protocol Id: 864
Note: This protocol is written for spotting fragmented, purified genomic DNA (titration of 1000 ng, 500 ng, 250 ng, 125 ng, 62.5 ng, 31.25 ng, and 15.625 ng) onto a positively charged nylon membrane using a 96-well dot blotting apparatus. Depending on the source and type of DNA, more or less DNA may be required for detection with the antibody.
Before Starting:
• Purify genomic DNA using a genomic DNA purification protocol or kit and sonicate
genomic DNA to generate fragments between 200 and 500 bp. DNA fragment size
can be analyzed by gel electrophoresis on a 1% agarose gel with a 100 bp DNA
marker.
• Cut a piece of nylon membrane to the size of the dot blot manifold.
• Wet nylon membrane with 10x SSC Buffer.
• Dry membrane by placing it in 96-well dot blot apparatus and applying vacuum.
NOTE: Due to the kinetics of the detection reaction, signal is most intense immediately following incubation and declines over the following 2 hr
posted November 2015
Protocol Id: 804
All Species Expected
Monoclonal antibody is produced by immunizing animals with 5-carboxylcytidine.
Methylation of DNA at cytosine residues is a heritable, epigenetic modification that is critical for proper regulation of gene expression, genomic imprinting, and mammalian development (1,2). 5-methylcytosine is a repressive epigenetic mark established de novo by two enzymes, DNMT3a and DNMT3b, and is maintained by DNMT1 (3, 4). 5-methylcytosine was originally thought to be passively depleted during DNA replication. However, subsequent studies have shown that Ten-Eleven Translocation (TET) proteins TET1, TET2, and TET3 can catalyze the oxidation of methylated cytosine to 5-hydroxymethylcytosine (5-hmC) (5). Additionally, TET proteins can further oxidize 5-hmC to form 5-formylcytosine (5-fC) and 5-carboxylcytosine (5-caC), both of which are excised by thymine-DNA glycosylase (TDG), effectively linking cytosine oxidation to the base excision repair pathway and supporting active cytosine demethylation (6,7).
TET protein-mediated cytosine hydroxymethylation was initially demonstrated in mouse brain and embryonic stem cells (5, 8). Since then this modification has been discovered in many tissues, with the highest levels found in the brain (9). While 5-fC and 5-caC appear to be short-lived intermediate species, there is mounting evidence showing that 5-hmC is a distinct epigenetic mark with various unique functions (10,11). The modified base itself is stable in vivo and interacts with various readers including MeCP2 (11,12). The global level of 5-hmC increases during brain development, and 5-hmC is enriched at promoter regions and poised enhancers. Furthermore, there is an inverse correlation between levels of 5-hmC and histone H3K9 and H3K27 trimethylation, suggesting a role for 5-hmC in gene activation (12). Lower amounts of 5-hmC have been reported in various cancers including myeloid leukemia and melanoma (13,14).
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