Abstract: Microinjection is a key method to animal gene transfer. Ejection pressure, ejection duration, tip diameter of the pipette are important factors that affect the dispensed volume of the ultramicroinjector. The injection controllers currently used in this field can’t accurately control the dispensed volume and thus lead to the low injection efficiency and survival rate. A kind of electrical controller microinjection controller with air as the pressure medium is described. Based on the derivation of theoretical model the relationship between dispensed volume and ejection pressure, ejection duration and tip inner diameter is experimented and analyzed applying multiple factor transformation regression design. The experiment results show that the calibrated microinjection controller can satisfy the requirements of gene transfer.

Key words: Droplet measurement, Gene transfer, Image processing system, Multi-factor orthogonal regression design, Ultramicroinjector controller