Designing an antibody for use in research is a time consuming process. In most cases, antibody production is limited in the host animal that can be chosen by the constraints of the animal facility. Even if the preferred host is mouse, the most commonly available animal, the injections and subsequent harvest of the antibodies is a long, drawn-out event. If the final goal is a monoclonal antibody, further purification steps still need to be undertaken to get the desired outcome. These and other reasons are what usually lead a researcher to consider an outside company for producing their required antibodies.
For most laboratories, it is the amount of the researcher’s time that is the driving factor for choosing a service to create a custom antibody. The ability to choose from a wider selection of host animals is usually only a small factor. The exception to this is, of course, researchers needing anti-mouse antibodies or other specific host animals. Most animal facilities have limited space, and keeping goats or other larger animals for antibody production is prohibitively expensive.
Most custom antibody services are willing to provide assistance for every individual step beginning with designing the antigen. Choosing the appropriate antigen is perhaps the most important part of the process and should be given the greatest consideration before the project begins. A laboratory can choose to have the purified peptide sent to them or let the antibody company continue with immunizing the selected host and on through purification of the antibody. Many companies will even validate and optimize the antibody before sending it out if the researcher needs the service.
The success of most projects requiring antibodies is highly dependent on the quality of the antibody used in the experiments. An antibody that has non-specific recognition of the target confounds the research and gives poor results. By using a company, a researcher increases the chances of successful outcomes to his or her science. When created in-house, these quality checks can add significantly to the amount of time that is required before the antibody is useful.
A second advantage to using a custom design company is the volume they are able to produce. With resources dedicated to antibody production, a company produces much more starting material and can screen a greater number of clones to find the one or ones that are the most specific to the antigen. Not only can they screen for antigen recognition, an antibody can be selected for optimal activity. If the desired effect is to be an agonist or antagonist, both activities can be tested for and specific clones identified.

Finally, some companies will continue to store the clones they have created for the researcher, meaning that the lab can request an additional supply of the antibody at a later date should the research prove to be worth continuing. It also serves as a secondary backup for resources in the event of a lab catastrophe.
When considering using the services of a custom antibody company, weigh the cost against not only the time required to produce the antibody, but also the quality and verification needed to receive a good product. Most researchers will find that the benefits are far greater and will choose to have their antibodies produced by a professional service.