Mice is an important model animal in developmental biology and reproductive biology research, and its embryo transfer technology is a key link in the research of in vitro fertilization, chimera, transgene, cloning, and embryo frozen seed bank. At present, we have successfully established a mouse non-surgical embryo transfer technology, using this technology to transfer 3.5-day blastocysts to the uterus of a 2.5-day pseudo-pregnant mouse. On average, 73% of the blastocysts can develop into a living newborn. This technology is better than surgery. The method of embryo transfer is simple and fast. It only takes tens of seconds to complete the operation process, saves costs, does not require surgery, is not susceptible to infection, painless, conforms to the principles of laboratory animal welfare, and can also be used for uterine drug treatment and other large animals and Research on human embryo transfer. The experimental steps are as follows:
一 Embryo preparation: Make 50 microliters of M2 droplets on a 60mm petri dish, and put a group of 5-10 blastocysts in each droplet.
2. Aspirate embryos: install the catheter in a 2.5 microliter pipette and adjust to 1.0 microliter; half-press the button of the pipette; deepen the tip of the catheter into the M2 drop, observe and aspirate the embryo under a dissecting microscope, and the suction is successful After that, remove the tube from the M2 drop to ensure that the liquid sucked does not exceed 3mm; tap the tube gently to make a 1mm bubble at the front end. If no bubbles appear, you can slowly adjust the pipette to 1.1 microliters.
Three-receptor preparation: anesthetize, the recipient mother mouse is injected with 0.4-0.5mL, 1.25% avertin (0.2mL/10g body weight); fix, hold the tail root of the mouse with the index finger and thumb, and hold it with the other three fingers The buttocks, and tilt it upwards; open the body, use the opener to open the vulva, open the cold fiber optic fiber, and observe the opening of the cervix.
Four transplantation: The catheter with the embryo sucked into the cervix, the arc is along the back of the mouse, when the base of the catheter reaches half of the open susceptor, gently press and slowly rotate the pipette, press it to the maximum At the bottom, inject all the embryos into the uterus, slowly withdraw the pipette, release the pressing finger when half of it is withdrawn, and finally check the catheter under the microscope to determine whether the embryo has moved in.