This intention of this chapter is not to provide a fully comprehensive listing of all consumables, and suppliers thereof, that may be used for micromanipulation. Rather, the emphasis is on the requirement for specific types of materials to perform different aspects of micromanipulation technique. In most instances, a given type of consumable is often provided by a number of different suppliers, the choice usually being determined by personal preference. In this respect, most of the suppliers listed are either internationally well established or those with which the authors have dealt with in the past. Therefore, although these may not be the very best available, in most instances they have at least been tried and have been proven suitable for the purpose for which they are intended.

‘Zona drilling’ was the term used originally to denote the technique of creating a hole in the ZP surrounding the oocyte (Gordon and Talansky, 1986). The first intuitive application of this procedure in human infertility was to provide a conduit via which spermatozoa could pass through the ZP (Cohen et al., 1988; Gordon et al., 1988). This approach to alleviating male-factor forms of infertility that were related to the inability of spermatozoa to bind to or penetrate the ZP was termed partial zona dissection (PZD). This involved physically cutting a hole or slit in the ZP using micropipettes. However, this approach was considered to be inefficient because it was suspected that partial or complete closure of the slit created might compromise sperm motility or even prevent access to the oocyte altogether. Therefore, the next logical step was to use ZD as a means of introducing spermatozoa directly into the PVS with the aid of a large microinjection pipette that could be passed through the hole thus created (Laws-King et al., 1987; Ng et al., 1988). This technique, originally termed ‘microinjection sperm transfer’ later became known as ‘subzonal insemination’. With the introduction of very fine and sharp microinjection pipettes, ZD soon became unnecessary for the SUZI technique, as it became possible to pierce the ZP directly. Osmotic manipulation of the oocyte prior to SUZI was usually applied to enlarge the PVS, so as to avoid damage to the oolemma.

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The successful development of micromanipulation techniques for ICSI and PGD has stimulated research into further potential clinical applications. Putative beneficial uses of this technology have included the use of empty ZPs for the cryopreservation of spermatozoa (Cohen et al., 1997a), the transfer of ooplasm from one oocyte to another (Cohen et al., 1997b), the transfer of a GV from one oocyte to an enucleated oocyte (Zhang et al., 1999), ploidy reduction by removal of pronuclei from polyploid zygotes (Rawlins et al., 1988), and the removal of fragments of cytoplasm from fragmented embryos (Alikani et al., 1999). Almost all of these techniques are still at an early research stage and have yet to be proven unequivocally to have beneficial clinical application. Indeed, some of these techniques have become controversial due to concern over their safety, such as the possible inheritance of defective mitochondrial DNA, which could lead to disease in later life. It is not within the scope of this book to review exhaustively all of the new applications currently being researched. However, some of these techniques merit further description by virtue of their perceived benefit to the enhancement of reproductive and therapeutic potential. Consequently, these will be discussed briefly in this chapter.

This practical 2003 handbook provides an extremely comprehensive and highly illustrated guide to micromanipulation techniques in assisted conception in a clinical setting. It includes detailed, illustrated descriptions of all the common micromanipulation systems currently in use in IVF laboratories around the world and clearly explains how to optimise their successful use. The volume covers state-of-the-art techniques including intracytoplasmic sperm injection (ICSI), and procedures such as assisted hatching and the blastomere biopsy (for preimplantation genetic diagnosis PGD). Valuable information on troubleshooting the potential mechanical and technical difficulties that can arise is provided to help all the practitioners of these techniques, including trainee embryologists and consultant obstetricians, and technicians and scientists involved in animal transgenesis and cloning. It will undoubtedly be of immense value to all doctors and scientists working with assisted reproductive technologies.

Glass micropipettes are precisely constructed microtools forming the basis of a variety of investigative and clinically relevant techniques. They are used extensively in basic cellular research as channels into cells. Through these channels, substances can be injected or cellular contents extracted.

A SHORT HISTORY AND BACKGROUND TO IN VITRO FERTILIZATION, INTRACYTOPLASMIC SPERM INJECTION AND ASSOCIATED TECHNIQUES

Eiichi Narishige established the Narishige Scientific Instrument Laboratory in Tokyo in 1953. Quickly becoming renowned throughout Japan for producing high-quality mechanical micromanipulators and stereotaxic equipment, Narishige concentrated on selling to physiology and neuroscience research facilities in Japan and, later, the West. The first hydraulic micromanipulator, a single-axis device designed to place microelectrodes into the brains of experimental animals, followed in 1969, and the first three-axis hydraulic micromanipulator was produced in the early 1980s (Cohen et al., 1992). The advent of three hydraulic axes controlled by a single joystick allowed true microsurgical manipulation in much the same way that the original Leitz and DeFonbrune joystick models had. The main advantage of the Narishige system over the traditional Leitz manipulator was the ability to mount the moving (slave) headstage on to the microscope, but with the joystick controller positioned remotely.