Sandwich Ab:XA Pair

Do you have an antibody and wish that you could find a partner for it that binds your target concurrently? Having a sandwich pair of affinity molecules that bind simultaneously to a target provides numerous advantages. A sandwich affinity pair helps tremendously to validate binding to the target (a very important consideration), enables greater assay specificity, and can improve assay sensitivity.

Using the X-Aptamer Selection Kit, you can readily develop a binding partner for your existing antibody at a very reasonable price.

X-Aptamer and antibodies complement each other, each having their particular advantages. Antibodies are comprised of amino acids, while X-Aptamers are primarily nucleic acids and; therefore, are about one-tenth the size of most antibodies. X-Aptamers and antibodies perform a similar function but bind a target differently – in an orthogonal manner. It is relatively difficult and expensive to develop a sandwich pair of antibodies to the same target, which is why so many antigens (targets) do not have a sandwich pair of Abs. The X-Aptamer Selection Kit enables virtually any scientist with access to basic laboratory equipment to develop an X-Aptamer sandwich partner for an antibody. It is very likely that the selected X-Aptamer will bind a different epitope than an Ab. The XA:Ab pair can then be used in many types of assays but especially to develop an Enzyme Linked Oligonucleotide Assay (ELONA) as depicted in the diagram below, which is the equivalent of an ELISA that uses two sandwich Abs.

Selecting an X-Aptamer binding partner for an Ab is very straightforward if the purified target is available. If the purified target is not available, then the existing Ab can be used to purify the native target from a sample to be used as the target in an X-Aptamer selection.

Examples of ELONA using one Ab and one X-Aptamer

OPG <expand page to show data like the FAQ> PPT Slide 7
pLDH <expand page to show data like the FAQ> PPT Slide 8
H1N1 NP <expand page to show data like the FAQ> PPT Slide 6
RSV FP <expand page to show data like the FAQ> PPT Slide 6