Introduction
The standard series of AURION immunogold reagents is intended for the two and three step detection of antigens. Although these approaches cover the majority of all applications there may occasionally exist a need for a direct label where the gold particles are coupled directly to the primary antibody or, more general, to a protein or peptide with specific binding properties. An example is found in working with specimens where substantial amounts of homologous immunoglobulins are present. A further example is found in the detection of receptors through labeled ligand molecules.

To fulfill these needs AURION offers a custom labeling service for antibodies, antibody fragments, proteins, and peptides with gold particles of any requested size, including ultra small gold particles. AURION designs and manufactures such custom conjugates in close co-operation and in agreement with the principal investigator.

Starting material and quality control criteria
Our custom labeling service is based on the coupling of up to 1 mg of protein or ligand*.
The custom prepared product is initially quality controled by AURION according to our in-house standards for instance with respect to size distribution and clustering. In agreement with the principal investigator the binding substance’s specific quality control criteria are determined. These are tailored for each individual assignment. As a matter of course the custom conjugate is approved only when both sets of quality control criteria have been met.

A few examples
AURION successfully conjugated a number of polyclonal antibodies, mouse monoclonal antibodies, F(ab’)2 and F(ab) fragments, high and low density lipoproteins, as well as peptides such as an Angiotensin derivative (octapeptide), Interleukin II, Tumor Necrosis Factor and a number of peptide hormones. So far the efficiency of coupling for the above mentioned custom conjugates has been greater than 70% on all occasions, while efficiencies up to 90% are no exception.

No cure, no pay
The custom labeling service is on the basis of “no cure, no pay”, with the exception that a small intake fee applies to each actual laboratory attempt. We invite you to contact us if you request information which is more tailored to your specific research applications.

* Our custom labeling is based on the conjugation of 1 mg of antibody molecule (complete IgG). For other macro molecules, e.g., antibody fragments, a molar equivalent applies. For low molecular weight ligands please inquire. As a rule AURION will only accept pure substances as starting material, either lyophilized or dissolved in a medium of known chemical composition. Interfering substances must not be present.