INTRODUCTION

Natalizumab (Tysabri®) is a humanized monoclonal antibody against the cell adhesion molecule α4-integrin used in the treatment of multiple sclerosis and Crohn’s disease. Tysabri® and was previously named Antegren®.  Natalizumab is administered by intravenous infusion every 28 days and reduces the ability of inflammatory immune cells to attach to and pass through the cell layers lining the intestines and blood–brain barrier.

The Natalizumab ELISA kit is designed to measure free Natalizumab with high specificity and sensitivity.

PRINCIPLE OF THE ASSAY

This assay employs the sandwich enzyme immunoassay technique. A precoated anti-Natalizumab 96 well plate is provided. Calibrator, quality control samples and test samples are pipetted into the appropriate wells.  Natalizumab present in biological matrices is bound by the immobilized capture antibody. After washing away any unbound substances, enzyme linked detection antibody is added to the wells. The plate is washed to remove any unbound antibody-enzyme reagent and a substrate solution is added to the wells for color development. The color development is proportional  to  the  amount  of  Natalizumab present  in test  samples and the concentration is calculated from the standard series.