Gene Pulser MXcell™ Electroporation System

A choice of exponential or square waveforms. Both exponential-decay and square-wave pulses have been used very effectively for both electroporation and electrofusion. The shape of the electroporation wave can have a significant effect on the transformation efficiency for different cell types. The Gene Pulser MXcell system generates both exponential and square waveforms, enabling you to choose the waveform and protocol that will work best for your cells.

Exponential-decay pulse. When a capacitor, charged to a voltage V₀, is discharged into cells, the voltage applied to the cells decreases over time in an exponential curve such that the voltage V at any given time t is given by V = V₀e^-(t/RC). In the special case where t = Τ, then V = V₀/e. The value CR is known as the time constant of the voltage decay. The shorter the time constant the faster the decay.

Square-wave pulse. Truncating the pulse from a capacitor after discharging it into the sample generates a square-wave pulse. The pulse length is the time the cells are subjected to the discharge. During the pulse, the voltage again decreases by an exponential decay so that at the end of the pulse the voltage is lower than at the beginning. This drop in voltage is called the pulse droop and it is measured as a percentage of the initial voltage.

Optimize Your Resources

Use fewer cells and less sample — siRNA or DNA — by defining your parameters. Optimizing your electroporation parameters will ensure that cell viability and transfection efficiency are at their highest levels.

GAPDH mRNA levels in Jurkat cells postelectroporation.

A siLentMer Dicer-substrate siRNA duplex (GAPDH) or a scrambled negative control (NC) was delivered using the Gene Pulser MXcell system and Gene Pulser electroporation buffer, or a competitor's electroporator and cell line-specific buffer kit. Gene knockdown was measured by qPCR.

A, GAPDH mRNA levels 4 hr postelectroporation.

B, GAPDH mRNA levels 24 hr postelectroporation.

After 4 hr, >88% knockdown was obtained using the Gene Pulser MXcell system and Gene Pulser electroporation buffer, compared to only 31% knockdown using a competitor's system.

Gene silencing in SK-N-SH cells electroporated with either a siLentMer GAPDH siRNA or a siLentMer nonspecific siRNA assessed using real-time RT-qPCR. Cells (3 x 10⁶/ml) were electroporated (20 ms square-wave pulse of 200 V and 2,000 µF) with 50 nM (A) or 100 nM (B) siRNA. Nonspecific siRNA (—); GAPDH siRNA (—). C, over 90% gene silencing was obtained in cells treated with 50 or 100 nM GAPDH siRNA () compared to cells treated with the corresponding concentration of nonspecific siRNA () (negative control). RFU, relative fluorescence units.

Time course of GAPDH gene silencing in Jurkat cells. Values were normalized to scrambled negative control (lime green); silencing of 88% of gene expression was observed in cells transfected with GAPDH siRNA (dark green).

siRNA delivery into neutrophils using a range of electroporation conditions. Neutrophils were electroporated using the indicated conditions in the presence of siRNA conjugated to Alexa Fluor 546, then imaged by fluorescence microscopy. MFI was used as an index of siRNA delivery into the cells. Under conditions below 300 V, transfection efficiency increased when capacitance was increased. RFU, relative fluorescence units.