20210629 microfluidics

PDMS

We made a new batch of PDMS and casted three new chips - Thomas' (25 um), Thomas' (50 um) and Annikens (100 um).

Passaging

When passaging the cells, we discovered that one of the flasks was completely covered with mold. We passaged the other flask as normal, splitting it into two new flasks. We also took some of the cells from this flask to put them into the chip covered with collagen.

Collagen

We made a new batch of diluted collagen to coat Thomas' chip from last time (25.06.2021). We used 10 uL of 17.5 M acetic acid and 10 mL of sterilized water to make a acetic acid dilution. Then we took 300 uL of this dilution and mixed it with 200 uL of collagen. We began injecting the collagen into the tubes using the syringe pump but decided there were too many bubbles in the tubes. We kept what was left of the collagen dilution. Then we mixed a new batch of diluted collagen and put everything into a new syringe to try again. Total amount of collagen was 0.5 mL. We managed to fill the chip with collagen without bubbles. After coating the chip with collagen we left the chip for one hour. Then we flushed the chip with PBS. This resulted in some big bubbles. The gas was not connected, so we could not use the Elveflow pressure controller to aspirate the chip. We used an empty syringe and the syringe pump instead, but this was less effective. As there was still bubbles in the chip, we desided not to inject cells.