AN AUTOMATED fertility lab etched in silicon has come a step closer with a
device that can grab hold of individual cells and manipulate them. Its tiny
silicon jaws could help researchers with the delicate task of handling eggs for
fertility research.
Jay Jakubczak and Murat Okandan at Sandia National Laboratories in
Albuquerque, New Mexico, took a sliver of silicon and etched it to form a
miniature clamp, like the jaws of a vice, spanning a channel just 20 micrometres
across. One of the silicon jaws is fixed, while its partner can be moved in and
out from the opposite side of the channel by a miniature hydraulic pump etched
into the silicon.
To test out the device, the researchers pumped red blood cells along the
channel. They found that by gently closing and opening the jaws they could trap
and release cells as they passed by. 鈥淲e can do about 10 per second,鈥� says
Jakubczak. 鈥淏ut you could array these devices and do lots at a time.鈥�
Advertisement
Jakubczak and Okandan call their cell-grabber Pac-Man, after the 1980s
computer game character that gobbles up ghosts. Unlike the original Pac-Man, it
releases the cells unharmed.
Okandan says he can use the same silicon-etching technology to replace the
jaw鈥檚 teeth with hollow silicon probes. These could puncture a cell鈥檚 membrane
as they grab it, and inject the cell with DNA. This would help automate a
difficult manual task in fertility and cloning research. Cells could also be
injected with drugs for pharmaceutical research.
Right now, the only alternative to piercing the membrane manually is to
expose the cells to a strong electric field. This tears holes in the cell so
that drugs can diffuse in, but the cell often dies too.
Handling eggs manually is an exceptionally delicate task that has to be done
under a microscope by highly skilled people. 鈥淰ery few people have mastered it,鈥�
says Kevin Eggan at MIT鈥檚 Whitehead Institute in Cambridge, Massachusetts, who
transfers nuclei into and out of animal eggs for cloning experiments 鈥淎 very
skilled person can do about 150 eggs in five or six hours,鈥� he says. Eggan says
the idea of an automated tool for manipulating cells is very interesting. 鈥淭he
technical hurdle is a large barrier鈥�, he says. 鈥淚t would be really wonderful if
there was some way to automate the procedure.鈥�