About IgG Corp
Founders. IgG Corp was founded in 1978 by three university medical center investigators: two endocrinologists, Drs. David N. Orth and Robert J. Workman, and an endocrinology laboratory director, Wendell E. Nicholson. Together they have decades of laboratory experience and have developed more than three dozen radioimmunoassays.
Purpose. IgG Corp was established with the aim of providing investigators with antisera which, while polyclonal, contain antibodies of such high affinity and specificity that peptide and steroid hormones can be measured with great accuracy down to the lower limits of their physiological concentrations in circulating blood. Radioimmunoassays using IgG Corp antisera accurately measure peptide and steroid hormones in unextracted plasma with lower assay limits generally in the 5-20 pg/mL and 0.1-2 ng/dL ranges, respectively.
About IgG Corp RIA Antisera
Production. Rabbits were immunized with peptide hormone fragments or steroid analogs conjugated to carrier protein in such a manner that the desired portion of the hormone antigen was displayed to circulating immune cells. The aim of IgG Corp was not to produce antibodies in every animal immunized, but rather to produce high-affinity antibody in just one of many animals. The resulting antisera were assessed for binding affinity, and animals that produced the requisite high-affinity antibodies were usually bled multiple times. Each bleeding was tested, some bleedings were pooled, and the specificity of the antibodies in the pool was characterized using a variety of structurally related hormones, hormone fragments and hormone analogs.
Stability. The pools were aliquoted in vials, lyophilized, sealed, and stored frozen. From time to time IgG Corp tests aliquots for binding affinity and specificity. There has been no evidence of change in the characteristics of any of the antisera over a period of more than three decades.
Long-Term Availability. Sufficient antiserum to prepare a minimum of several million assay tubes according to the protocol recommended by IgG Corp was required to make the antiserum available to investigators. Thus, IgG Corp customers are assured of many years’ supply of the same antiserum with exactly the same characteristics as their very first purchase.
Sensitivity. IgG Corp does not ask you to purchase an antiserum without knowing all you need to know about it. The description of each IgG Corp antiserum includes its binding characteristics: the amount of unlabeled peptide, steroid or other substance being measured required to displace 10 percent of the labeled tracer (its sensitivity) and the amounts that are required to displace 50 and 80 percent of the labeled tracer, indicators of the slope of the curve (its accuracy) and its useful range.
Specificity. In the description of each IgG Corp antiserum its percent crossreactivity with structurally related hormones is indicated. Especially in the case of steroid hormone antisera, specificity is potentially a significant problem because related steroids may be circulating in the blood in concentrations many hundred-fold greater than the steroid being assayed.
Species Specificity. The description of each IgG Corp antiserum also indicates its specificity for animal species. Many of the antisera are interspecific, such as several of the steroid antisera and those like IgG-ACTH-1 antiserum, which contains antibodies directed at the corticotropin (ACTH) 1-24 sequence that is common to all known species. Others are directed at species-specific sequences and may therefore be useful in measuring exogenous and endogenous hormones in the same individual, even in the same sample, such as plasma from patients who have been injected with oCRH, using IgG-hCRH-1 and IgG-oCRH-1 antisera..
ABOUT IgG Corp IMMUNOCYTOCHEMISTRY ANTISERA
IgG Corp antisera for immunocytochemistry, immunoprecipitation of hormones in vitro, or preparation of immunoaffinity agarose gels were produced in exactly the same manner as antisera for radioimmunoassay. They have the same high specificity as IgG Corp antisera for radioimmunoassay, and their binding affinities, while not sufficiently high for radioimmunassay, are more than adequate for these purposes. Furthermore, the total binding capacity of each of these antisera has been determined.
ABOUT OTHER IgG Corp REAGENTS
Radioimmuoassay. IgG Corp provides other necessary radioimmunoassay reagents, such as goat anti-rabbit gamma globulin serum (IgG-GARGG), donkey anti-goat gamma globulin serum (IgG-DAGGG), donkey anti-sheep gamma globulin serum (IgG-DASGG), normal nonimmune rabbit serum (IgG-NRS), normal nonimmune goat serum (IgG-NGS), normal nonimmune sheep serum (IgG-NSS) and the proteolytic enzyme inhibitor aprotinin (IgG-Aprotinin).
Reference standard and radiolabeled tracer compounds are readily available from other suppliers.