title: Development of a vibratory microinjection method.
abstract: To reduce cellular damage by pronuclear microinjection and nuclear transfer, we have recently developed a vibratory microinjection method. A micropipette was fixed to a piezoelectric ceramic with a resonance frequency of 70 kHz. When this micropipette was vibrated, it easily entered a mouse-fertilized egg without any sharp depression of the cell body, whereas a sharp, deep depression at the insertion site was observed when the micropipette was not vibrated. A depression rate defined as a rate of a depth of depression over an original cell diameter was utilized as an index of cellular deformation. The depression rates with and without vibration were 11.1 +/- 5.2% (N = 24) and 40.4 +/- 8.8% (N = 16), respectively (P < 0.0001, Student's t-test). In conclusion, the vibratory microinjection method is a new, useful option for gene transfer because it resulted in much less cellular deformation, therefore implicating less cellular damage.
authors.affiliation: College of Science and Engineering, Tokyo Denki University, Japan. miyawaki@b.dendai.ac.jp
authors.forename: F
authors.initials: F
authors.lastname: Miyawaki
authors.forename: Y
authors.initials: Y
authors.lastname: Arai
authors.forename: T
authors.initials: T
authors.lastname: Morisaki
authors.forename: S
authors.initials: S
authors.lastname: Ahmed
authors.forename: S
authors.initials: S
authors.lastname: Omata
authors.forename: Y
authors.initials: Y
authors.lastname: Fukui
mesh_terms: D000818:Animals; D003593:Cytoplasm; D004867:Equipment Design; D008845:Microinjections / Q000295:instrumentation* / Q000379:methods; D010063:Ovum / Q000166:cytology*; D014465:Ultrasonics; D014732:Vibration; D015044:Zona Pellucida