Sangmi Lee, Trine Grønhaug Halvorsen, Léon Reubsaet
University of Oslo, Department of Pharmacy, Oslo, Norway
Email: sangmi.lee@farmasi.uio.no
A smart affinity sampler is a modified filter paper that serves as a microsampling tool to quantify low abundance proteins in biological samples like blood and plasma. The typical modification is the immobilization of monoclonal antibodies (mAbs) which can capture target proteins.
The fabrication of these smart affinity samplers is a two-step process. In the first step, common filter paper (Whatman filter paper, grade CF 12) is functionalized with divinyl sulfone (DVS), where the cellulose backbone of the paper and the vinyl groups of DVS form covalent bonds. In second steps, mAbs are immobilized on the paper by forming covalent bonds with DVS.
The use of the smart affinity sampler is based on the binding of the target protein to the immobilized mAbs when a drop of sample is added on the paper. Following binding, several washing steps, protein digestion, and solid-phase extraction (SPE) are performed. The resulting peptides are analyzed using LC-MS to quantify the concentration of specific proteins.
Our research group has developed and fully validated these smart affinity samplers, as described above, and compared with other methods such as electrochemiluminescence immunoassay (ECLIA) and immunocapture with magnetic beads. The results demonstrated that the modified filter paper performs comparably to these benchmarks.
This poster describes my PhD project which aims to develop a new generation of smart affinity samplers. These new generation samplers contain multiple mAbs on a paper which potentially allow, the simultaneous capture and analysis of several target proteins. The purpose of this project is to develop a more advanced sample collection tool that can be practically used for diagnostics and clinical assays using only a single drop of blood. A key advantage of this approach is that patients can collect samples themselves at home without visiting a hospital. This is particularly beneficial for those who have difficulty accessing healthcare facilities due to distance or mobility issues.