Specific binding of cancer cells using a microchamber array functionalized with antibodies

Specific binding of target suspended metastatic cancer cells to an antibody-functionalized surface utilizing a microfluidic device has experimentally been investigated under various conditions. The microfluidic devices, fabricated in silicon using DRIE process, consisted of a 5×5 micochamber array; each 1mm×1mm in area, and 50pm in depth. The oxide surface of the microchammber array was functionalized with various antibodies immobilized on a protein G layer. The microfluidic device design allows accurate counting of cells loaded into each microchamber and, thus, enabling a reliable counting of cells captured from homogeneous suspensions. The effects of cell suspension concentration, incubation times and ambient temperature on cell capture efficiency have been examined. Furthermore, to evaluate the specificity of the cell-surface interaction, several cell cancer types expressing different membrane receptors have been incubated on surfaces functionalized with various counter receptors. Specific binding of up to 100% of the suspended cells is observed when using surfaces functionalized with counter receptors matching the cell receptors; otherwise, non-specific binding of less than 15% of suspended cells is obtained if the functionalized counter receptors do not match the cell receptors.