DOX resistance
A total of 1 10^5 cells/10 L was suspended in culture medium, and 1 L of the solution was gently added to thechip using a pipette with a tip through the cell seeding hole. The next day, 250 L ofculture medium and culture medium containing 1.5 M DOX were added to two of the diagonalreservoirs, and 50 L of culture medium was added to the rest of the diagonal reservoirs. After 11 days, trypsin (Gibco) was addedto the chip, which was incubated at 37  for 5 min.