Preparation and detection of pipettes for microinjection / 西安交通大学学报(医学版)

ABSTRACT

Objective To introduce an optimized practical method of making and detecting pipettes for microinjection.Methods Transfer pipette was made from hard glass capillary. We softened the hard glass capillary by rotating it in a spirit-lamp flame,then moved out from the flame and quickly pulled it into two transfer pipettes.After broken by a grinding wheel,the tip of the pipette was fire-polished by quickly touching the flame to make a fine opening.A hard glass capillary (1.0 mm,ouside diametre)was pulled into two holding pipettes by pipette Puller.The pipette shoulder was broken at desired position with a grinding wheel,then the fine pipette tip opening was heated by a microforge and shrinked into a diameter -15 μm.Injection pipette could be made directly from a capillary with filament by Puller.The solution loaded injection pipette and holding pipette were assembled into the micromanipulator and could be checked before use.We transfered both pipettes into the zygotes media drop,touched the holding pipette with the tip of the injection pipette to make a "suitable"opening.Then we switched injection pipette to the mineral oil and applied injection pressure through the injector to check whether the solution could come out of the tip smoothly and at a proper speed.It could be further verified by pronucleus microinjection of zygotes.Results The results showed that the method introduced in this paper could produce suitable pipettes for zygote microinjection.In particular,the method of detecting the opening of the injection pipette was helpful for achieving high efficiency of zygote microinjection.Conclusion The method introduced here to make and detect pipettes for microinjection is very helpful for establishing a standard microinjection manipulation procedure and improving the efficiency of zygote microinjection.