Week 3: Hardware

Class protocol reference

Making the electroporator

Teja said not to share too much about the project, but the main genius is using a fly swatter, which jacks up voltage to a very high level for a very short period of time, just as an electroporator does. The voltage supply is provided through a USB cable, because that provides a constant 5V regardless of power source. Controlling the voltage is done with a calibrated potentiometer.

Making the cuvette

The metallic sides of the cuvette are aluminum tape wrapped around plastic blocks, separated by a thin plastic card. Charge for around 5s to build up the voltage and release switch to discharge into cell.

Results and Some Thoughts

Apparently none of the bacteria were transformed successfully. Some possible reasons:

• The electrocompetent E. coli cells were left on ice for around half an hour after they had thawed. This is much longer than what I usually do, which is do transform as soon as possible after thawing. The cells lose competency very quickly after thawing.
• We didn't recalibrate after switching out one of the resistors, and didn't measure voltage output - perhaps it was too high (killed cells) or too low (cells weren't sufficiently shocked)