In Vitro Fertilization (IVF)

A main criteria for successful IVF is the use of sperm with acceptable motility, concentration, and forward movement. If one or more of these parameters is suboptimal, the ability to fertilize oocytes can be severely limited. In these cases, an XYClone™ laser is used to create 2-3 holes in the zona pellucida of each oocyte providing a means for less motile or less progressive sperm to penetrate the oocyte and induce fertilization. This procedure has greatly enhanced the fertilization efficiency of various genetically-modified lines and is a vital tool in the rescue of valuable rodent strains. Charles River Laboratories

Benefits of Laser-assisted IVF

By opening the zona pellucida of oocytes with the XYRCOS or XYClone laser, increased levels of fertilization may be obtained with certain inbred mouse strains or with poor quality sperm.

  • Increase fertilization rates with mutant and low motility sperm
  • Increase overall throughput and production
  • Significantly reduces the need for ICSI

 laser-assisted ivf in mouse

A Simple Technique to Improve IVF in Mice without Micromanipulation


  • Zona laser dissection of mouse oocytes significantly improved the fertilization rate following IVF.
  • This simple swift technique avoided micromanipulation and problems associated with ICSI. Furthermore, the reduced operator time allowed numerous oocytes to be treated in a short period.

Laser-assisted IVF Fertilization Percents

Laser-assisted ICSI using the XYClone consistently achieved successful fertilization (up to 44% reported) utlilizing thawed sperm that yielded 0% fertilization via conventional IVF. It has also shown to significantly increase the fertilization rate of known low fertilization sperm/oocyte combinations. Kathy Mohr, Facilities Director, Mutant Mouse Regional Resource Center, University of North Carolina at Chapel Hill

laser-assisted IVF

Fresh sperm (wild type & mutant)
C57BL/6 sperm + CD-1 oocytes

Regular IVF
WT Sperm
Laser assist IVF
WT Sperm
 57%  68%
 36%  92%
 85%  75%
 62%  58%
 48%  69%
Regular IVF
Mutant Sperm
Laser assist IVF
Mutant Sperm
 0%  40%
 0%  29%
 0%  34%
 0%  44%
  0%  14%


Using Thawed Sperm: C57BL/6 sperm + oocytes

Regular IVF Laser assist IVF
 20%  47%
 28%  44%
 25%  52%
 5%  29%
 1%  5.5%


There was normal development to blast and onward to hatching using XYClone laser for assisted IVF. Oocytes undergoing laser assisted IVF hatched 8-12 hours sooner than conventional IVF.

laser-assisted IVF mouse hatching embryos