Rink K, Delacrétaz G, Salathé R P, Senn A, Nocera D, Germond M, De Grandi P, Fakan S
Laboratoire d'Optique Appliquée, Ecole Polytechnique Fédérale de Lausanne, Switzerland.
Lasers Surg Med. 1996;18(1):52-62. doi: 10.1002/(SICI)1096-9101(1996)18:1<52::AID-LSM7>3.0.CO;2-Q.
A non-touch laser-induced microdrilling procedure is studied on mouse zona pellucida (ZP).
STUDY DESIGN/MATERIALS AND METHODS: A 1.48-microns diode laser beam is focused in a 8-microns spot through a 45x objective of an inverted microscope. Mouse zygotes, suspended in a culture medium, are microdrilled by exposing their ZP to a short laser irradiation and allowed to develop in vitro.
Various sharp-edged holes can be generated in the ZP with a single laser irradiation. Sizes can be varied by changing irradiation time (3-100 ms) or laser power (22-55 mW). Drilled zygotes present no signs of thermal damage under light and scanning electron microscopy and develop as expected in vitro, except for a distinct eight-shaped hatching behavior.
The microdrilling procedure can generate standardized holes in mouse ZP, without any visible side effects. The hole formation can be explained by a local photothermolysis of the protein matrix.