Development of an automatic magnetic immunostaining system for rapid intraoperative diagnosis of cancer metastasis

Magnetic immunostaining provides a novel technique for rapid intraoperative diagnosis of cancer metastasis and its characteristics in lymph nodes. Previous studies have shown the effectiveness of this technique using the manual staining process. However, to make this technique feasible for use in hospitals, establishing an automatic process is important. Thus, the objective of this study is to realize a device for immunostaining using magnetic fields that could not only automatically stain the samples, but also wash the specimen and change experimental solutions as well. The specifications for our prototype device were determined based on the manually performed experiments. We successfully fabricated a prototype device and demonstrated automatic immunostaining using it. The device completed, within 10 minutes, processes of blocking the specimen, injection of the magnetic beads, antigen-antibody reaction, and washing out the beads. The reaction took 1 minute, which was significantly shorter than that of conventional immunostaining. The device is expected to provide improved reproducibility of staining because of its automated processes.