Often for signal amplification and detection purposes, purified antibodies are conjugated to enzymes, fluorophores, or haptens, such as horseradish peroxidase (HRP), alkaline phosphatase (AP), rhodamine, fluorescein isothiocyanate (FITC), or biotin. The various antibody conjugates have differential stabilities and require different buffers and storage conditions to retain their maximal activity. The list below provides the standard antibody buffers and storage conditions for purified antibodies and antibody conjugates. Note that these are general guidelines. Always consult the datasheet accompanying the antibody for specific storage conditions for each specific antibody.
Standard Antibody Concentrations
Antibody Storage Conditions
Figure 1.Principle Antigen Detection
Secondary antibodies are often used to indirectly detect an antigen to which a primary antibody is first bound. Hence, it is important to select a secondary antibody that has specificity for the antibody species and isotype of the primary antibody and is conjugated to a detectable tag or label for detection. Consider the following points: