Immunochemistry

For most investigational purposes, crude animal sera, murine ascites, or in vitro propagated monoclonal antibodies are acceptable and satisfactory reagents. At times, however, the sensitivity and specificity of assays can be enhanced by the use of antibody that has been purified away from contaminating biological products. Further modifications of immunoglobulin, such as enzyme-labeling or radio-labeling and enzymatic or chemical digestion, also require a purified product. Spring Valley Laboratories, Inc. offers a variety of purification procedures aimed toward producing a purified immunoglobulin product suitable to the budget and requirements of the individual investigator.

Each of the chromatographic techniques listed below may be performed directly after the initial precipitation procedure, or they may be combined for various levels of immunoglobulin purification. Spring Valley Laboratories is available to discuss your requirements.

Precipitation

Ammonium sulfate precipitation or caprylic acid precipitation is an initial step in the purification of immunoglobulin. The resulting immunoglobulin product may be suitable for some analyses in the laboratory. It is the least expensive purification procedure that Spring Valley Laboratories offers. The precipitation product is supplied to you after dialysis against phosphate-buffered saline or a buffer of your choice. Precipitation is also a required first step prior to all the chromatographic techniques listed below.

Ion Exchange Chromatography

Spring Valley Laboratories uses DEAE (diethylaminoethyl) matrix for the further purification of immunoglobulin from animal sera, murine ascites, or in vitro propagated monoclonal antibodies. The pH of the precipitation product is raised above the isoelectric point of the immunoglobulins in that product. The immunoglobulin is allowed to bind to the matrix, impurities are washed away, and the bound immunoglobulin is then eluted under gentle conditions. The resulting immunoglobulin product can be further purified or delivered to you after dialysis against phosphate-buffered saline or a buffer of your choice.

Protein A/G Chromatography

The bacterial products protein A and protein G have varying affinities for immunoglobulin from different animal species. Spring Valley Laboratories uses the protein A/G matrix which offers the highest binding affinity for the immunoglobulin being purified. The immunoglobulin from precipitation or ion exchange chromatography is allowed to bind to the protein A/G matrix, impurities are washed away, and the bound immunoglobulin product can be further purified or delivered to you after dialysis against phosphate-buffered saline or a buffer of your choice.

Antigen Affinity Chromatography