Robin Cook
Shock

The human egg cell, or oocyte, that was snared by the slight suction exerted through the blunt end of the holding pipette was no different from its approximately five dozen siblings. It was merely the closest to the end of the tiny glass rod when the rod came into the technician's view. The group of oocytes was suspended in a drop of culture fluid under a thin layer of mineral oil beneath the objective of a powerful dissecting microscope. The oil prevented evaporation. It was vitally important that the environment of these living cells stay in an appropriate steady state. Like the others the fixated oocyte appeared healthy with an appropriate granularity of its cytoplasm. Also like the others its chromatin, or DNA, fluoresced under ultraviolet light like miniature fireflies in a pea-soup fog. The only evidence of the cell's earlier rude aspiration from its developing follicle were the ragged remains of its corona radiata of granulosa cells adherent to the comparatively dense envelope called the zona pellucida. All of the oocytes had been yanked from their ovarian nest prematurely and then encouraged to mature in vitro. At that moment they were ready for spermatic penetration, but that was not to be the case. These female gametes were not to be fertilized.

Another pipette entered the visual field. This was a more lethal-appearing instrument, particularly beneath the microscope's strong magnification. Although in reality only twenty-five millionths of a meter in diameter, it looked like a sword with a tip beveled to needlepoint sharpness. Inexorably it closed in on the hapless, immobile gamete and indented the cell's zona pellucida. Then with a practiced tap by the experienced technician on the pipette's controlling micrometer, the end of the pipette was plunged into the cell's interior. Advancing to the fluorescing DNA, a slight suction was applied to the pipette's interior and the DNA disappeared into the glass rod.

Later, after ascertaining that the gamete and its sisters had withstood the enucleation ordeal as well as could be expected, the cell was again immobilized. Another beveled pipette was introduced. This time the penetration was limited to the zona pellucida, sparing the oocyte's cell membrane, and instead of suction being applied, a tiny volume of fluid was introduced into what's known as the perivitelline space. Along with the fluid came a single, comparatively small, spindle-shaped adult cell obtained from a buccal scraping of an adult human's mouth.

The next step involved suspending the gametes with their paired adult epithelial cells in four milliliters of fusion medium and placing them between the electrodes of a fusion chamber. When the gametes were all appropriately aligned, a switch was thrown sending a ninety-volt electrical pulse through the medium for fifteen millionths of a second. The result was the same for all the gametes. The shock caused the membranes between the enucleated gametes and their adult cell partners to dissociate momentarily, fusing the two cells.

Following the fusion process the cells were placed in an activation medium. Under chemical stimulation each gamete that had been ready for fertilization prior to the removal of its DNA now worked magic with its adopted full complement of chromosomes. Following a mysterious molecular mechanism, the adult nuclei forsook their previous epithelial duties and reverted to their embryonic roles. After a short period of time each gamete began to divide to form individual embryos that would soon be ready for implantation. The donor of the adult cells had been cloned. In fact, he'd been cloned approximately sixty times…

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