Eppendorf Piezo-actuated Mouse ICSI (intracytoplasmic sperm injection) - Manual

Hadi Hajarian, Laboratory of In Vitro Fertilization, Agro-Biotechnology Institute (ABI), Malaysia
Ko Kwan Mor, Eppendorf Asia Pacific Headquarters, Malaysia
No 037 | September 2011 - revised August 2012
Userguide
ICSI (intracytoplasmic sperm injection) is an important and commonly used assisted reproductive technology in
both, humans and animals. The Mouse is one of the most common model organisms of choice to study mammalian
fertilization. However, the ability to fertilize mouse eggs successfully by sperm injection has been hard to achieve due
to the fact that the metaphase II mouse oocytes are extremely sensitive and convential ICSI gives low survival rates
[1]. This problem can be solved with piezo-actuated micromanipulation where the capillary advances a very short
distance at a very high speed. This enables the capillary to penetrate the cell membrane with minimum distortion of
the cell and yields to high survival rates. The microinjection workstation required for this technique is very similar to
standard ICSI, but with the addition of a piezo-assisted unit attached to the capillary holder. In this Userguide, the
use of the Eppendorf PiezoXpert in combination with the Eppendorf TransferMan
® NK 2 workstation is shown and
parameter settings as well as optimization of the piezo-actuated microinjection procedure itself are discussed.
Abstract
While this conventional ICSI technique has been very suc-
cessful in humans, it has proven unsuccessful in mice [2].
This is due to a lower viscosity of the ooplasm. Thus wound
healing capacity of mouse oocytes is inferior to that of hu-
man oocytes. Furthermore, the oolemma of mouse oocytes
is much more elastic than that of human oocytes. Suc-
cessful ICSI in mice was first demonstrated by Kimura and
Yanagimachi [3] using piezo-actuated micromanipulation,
which is far less traumatic than the conventional method.
This method proved to increase survival as well as fertiliza-
tion rates of oocytes after sperm injection [3].
Eppendorf has a long tradition in the area of conventional
ICSI. In particular, the Eppendorf TransferMan NK 2 system
is an electronic micromanipulation system that offers a num-
ber of useful features for ICSI. In combination with the piezo
impact unit PiezoXpert, Eppendorf is offering a complete
system for both, conventional ICSI and piezo-actuated ICSI
(Figure 1, 2).
Introduction
Piezo-actuated Mouse ICSI (intracytoplasmic
sperm injection) using the Eppendorf PiezoXpert®
Fig. 1: Actuator of PiezoXpert mounted onto the right arm of
the manipulator (Eppendorf TransferMan NK 2).
Intracytoplasmic sperm injection (ICSI) is a technique that
involves the direct transfer of a single sperm into the oocyte
cytoplam via a glass capillary with a spike.