Our cuvettes are known as the "Potter-style" cuvettes, and they fit most electroporators that accept a standard size cuvette.
How can I avoid arcing during electroporation of E. coli?
When electroporating cells at high voltage in conductive buffers, arcing may occur. MgCl2 and PO4 in particular are very conductive.
Some suggestions:
1) Keep ionic strength of cloning reactions to a minimum. If reaction buffers contain high salt, dilute DNA sample in water or TE buffer before electroporation.
2) Minimize addition of conductive ions. The volume of DNA solution should not exceed 5% of the total reaction. Example: 2 ?l DNA per 40 ?l of cells.
3) Be sure no air bubbles are present.
4) Make sure the electrical contacts are clean and tight. Wipe away any condensation on the outside of the cuvette.
5) For best results, the cells should be aliquoted into the bottom of the gap - tap the cuvette gently to help the cells settle to the bottom.
What is meant by "field strength" (kV/cm) when determining settings for electroporation? What are typical settings for different cell types?
The two most important electrical parameters for consideration in electroporation are pulse length and field strength. Field strength is defined as volts/centimeter, where V is equal to the initial peak voltage and cm is equal to the measurement of the gap between the electrodes of the cuvette in centimeters. For example, during electroporation of bacteria at 1,500 Volts in a 0.1 cm cuvette, the field strength would be 15,000 volts/cm, or 15 kV/cm. Typically, electroporation of bacteria requires field strengths of greater than 15 kV/cm. Yeast cells require 6-8 kV/cm, and mammalian cells often require optimization between 0.5 to 2.5 kV/cm.
What is the maximum volume of E. coli (bacterial) cells that can be electroporated in a 0.1 cm cuvette?
20-80 ul is a general suggested volume, but follow the optimized protocols for the cells and cuvettes that you are using.