Carrier Free Antibodies

Antibodies are essential tools for a broad range of immunoassay techniques, including Enzyme-Linked Immunosorbent Assay (ELISA), Immunocytochemistry (ICC), Western Blotting (WB), and Immunohistochemistry (IHC). They may be used for direct detection, during which the primary antibody features a label such as an enzyme or a fluorescent dye. Alternatively, indirect detection pairs unlabeled primary antibodies with labeled secondary antibodies. An advantage of direct detection is that it allows for multiple antibodies from the same host species to be combined in the same experiment. Direct detection can also save time by eliminating the need for a secondary antibody incubation step and any associated washes. However, whilst we offer a vast array of labeled and unlabeled secondary antibodies, your primary antibody of interest may not be available with your desired label as an off-the-shelf product. In this situation, you may wish to consider performing antibody labeling in-house on carrier free antibodies.

Various antibody-labeling kits have been developed, many of which involve little more than adding the antibody to the lyophilized label and incubating at room temperature. However, antibodies must meet certain criteria for the labeling reaction to go ahead. These include being purified (i.e., not in the form of ascites fluid, crude serum, or tissue culture supernatant) and above a certain threshold concentration (usually 1 mg/ml). It is also important for the antibody to be in a suitable buffer for conjugation. Critically, the buffer should be free of additives such as Bovine Serum Albumin (BSA), Gelatin, and Glycerol, and preservatives such as Sodium Azide or Thimerosal, all of which can interfere with the conjugation reaction. For example, BSA and Gelatin can sequester the label, while Sodium Azide can both reduce the conjugation efficiency and irreversibly inhibit Horseradish Peroxidase (HRP), a common enzyme label.

To simplify the labeling process, we offer a wide range of carrier free antibodies. These are typically formulated in Phosphate Buffered Saline (PBS) and supplied at a concentration of 1 mg/ml. In addition, our carrier free antibodies may also be of guaranteed high purity, which is often confirmed by SDS-PAGE, and low endotoxin. To check that the antibody labeling reaction has been effective, it is recommended to run a comparative analysis, using the labeled antibody for direct detection and the unlabeled antibody for indirect detection in the chosen application. If the labeling reaction has been successful, a similar staining pattern will be seen in both settings. Explore our range of carrier free antibodies below and discover more, for less.