Marker ink based dye as a tool for intravital high-resolution visualization of cells on a silicon

When creating new bioelectronic devices, including bioimpedance cytosensors, there is a need for optical monitoring of cell interactions with bioelectrodes. Typically, fluorescent dyes are used for this purpose, which are usually expensive and require strict storage conditions. In this paper, we propose a technology for visualizing living cells on opaque surfaces such as silicon using do-it-yourself low-cost dye called ABDS (A Beauty Dye for Staining), which is based on permanent marker red ink. We have shown that the use of ABDS allows one to obtain more detailed images of cells in respect to cost-free reflected light modes without using any dye at all. Moreover, the ABDS utilization makes it possible to study cells at the edge of the opaque bioelectronic device cell culturing chamber, which is difficult when using simple reflected light modes due to strong optical distorsions caused by the formation of a cells medium meniscus.