Streptavidin AlphaPlex™ 545 Acceptor Beads 250 µg

The introduction of enzyme-linked immunosorbent assays (ELISAs) in the early 1970’s offered researchers a non-radiometric immunoassay platform without compromising sensitivity. Over the last 50 years scientists have made huge strides in disease research and drug discovery and a demand for greater assay throughput and sensitivity has evolved. In response, more robust immunoassays have been developed to address some of the limitations of the standard, colorimetric ELISA.

Find out about the most common limitations of traditional ELISAs and how different ELISA alternative technologies address these limitations.

Anti-inflammatory monoclonal antibody drugs that specifically target TNFα, such as Humira^®, have been highly successful in the market. As patents expire on these top-selling drugs, effort has been placed on developing biosimilars. Biosimilars differ from small molecule generic drugs in that their chemical structure does not have to be exactly the same as the patented drug. Therefore, the FDA has stringent requirements for proving that the biosimilars have the same efficacy and safety profile as the patented drug. Companies that develop biosimilars are tasked with proving that the biosimilar shows equivalent pharmacokinetics as the patented drug.

Proving “biosimilarity” involves comparing parameters such as overall exposure, absorption, half-life, and clearance time using patient samples. Sensitive, robust, and fast assays are needed to measure these parameters. Traditional methods for detecting and quantifying these drugs in patient samples include time-consuming, wash-based ELISA and MSD methods. In contrast, AlphaLISA allows for fast, no-wash, high-throughput detection and quantification of the drug of interest in a variety of sample matrices. Here, we demonstrate the application of AlphaLISA for detecting biosimilars targeting TNFα.

Alpha has been used to study a wide variety of interactions, including protein:protein, protein:peptide, protein:DNA, protein:RNA, protein:carbohydrate, protein:small molecule, receptor:ligand, and nuclear receptor:ligand interactions. Both cell-based and biochemical interactions have been monitored, and applications such as phage display, ELISA, and EMSA (electrophoretic mobility shift assay) have been adapted to Alpha.

This guide presents the simple conversion of an ELISA or other immunoassay to an AlphaLISA® immunoassay.

AlphaScreen® and AlphaLISA® are bead-based assay technologies used to study biomolecular interactions in a microplate format. The acronym “Alpha” stands for Amplified Luminescent Proximity Homogeneous Assay. The assay does not require any washing steps. Binding of proteins or other binding partners captured on the beads leads to an energy transfer from one bead to the other, ultimately producing a luminescent signal.