Real-time monitoring of the cell agglutination process with a quartz crystal microbalance

The real-time monitoring of the agglutination process of human hepatic normal cells (L-02) at the quartz crystal microbalance (QCM) gold (Au) electrode was performed. Two lectins, concanavalin A (Con A) and wheat germ agglutinin (WGA), induced the cell agglutination, resulting in the different Deltaf(0) and DeltaR(1) responses from those caused by the normal cell attachment and growth. The cell-Con A-cell aggregates had higher affinity for the Au substrate due to the excellent adsorption ability of Con A, which was revealed by increased Deltaf(0) and DeltaR(1) shifts and the obvious mass effect of QCM. In contrast, the lower adsorption ability of cell-WGA-cell aggregates was related to the same characteristic of WGA, presenting the decreased Deltaf(0) and DeltaR(1) responses and the time-extended adhesion phase. Parallel microscopic observation experiments were also carried out and exhibited comparable results. The Deltaf(0) responses during the processes of cell growth and cell agglutination were analyzed using the equations Deltaf(0)=alpha(0)+alpha(1)e(-t/tau(1))+alpha(2)e(-t/tau(2))+alpha(3)e(-t/tau(3)) and Deltaf(0)=alpha(0)+alpha(1)e(-t/tau(1))+alpha(2)e(-t/tau(2)), respectively. Furthermore, the current work proved that the QCM measurement technique based on cell agglutination was useful for discriminating hepatic normal cells (L-02) and hepatic cancer cells (Bel7402).