Word: colis
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...ligase (from the Latin word meaning to bind), which acted as a form of genetic glue that could reattach severed snatches of DNA. Using their new biochemical tools, the scientists embarked upon some remarkable experiments. As usual, they turned to their favorite guinea pig, a lab strain of E. coli, and soon they had learned to insert with exquisite precision new genetic material from other, widely differing organisms into the bacteria (see diagram...
...coli did not merely accept the hybrid plasmids. When the bacteria reproduced-by dividing and thus doubling-at a rate of about once every 30 minutes, they created carbon copies of themselves, new plasmids and all. In only a day, one bacterium could make billions of duplicates of a transplanted gene...
...worrisome experiments, but also to press NIH to establish levels of safety that should be required for different experiments. In addition, they decided that precautions to keep research organisms from escaping from laboratories had to include "biological containment." This required the creation of mutated strains of E. coli so disabled that they could live nowhere but in a test tube. If they did escape their special broth and enter the atmosphere-or human gut-they would die almost instantly...
...against the potentially most dangerous experiments. They also provide two principal lines of defense against lesser hypothetical risks. They establish four levels of physical containment; these range from standard laboratory precautions (dubbed "P-l") for experiments in the lowest-risk category-say, injecting harmless bacterial genes into E. coli-to ultrasecure laboratories ("P-4") for work with animal tumor viruses or primate cells. At present, two new P-4 facilities are almost ready. One is a gleaming white trailer parked behind a bar bed-wire fence on the grounds of the National Institutes of Health in Bethesda...
...development of the recombinant DNA technique ushered in a new era of genetic engineering-with all of its promise and possible peril. The lowly organism that currently plays the largest role in the process is the E. coli bacterium. This microbe-a laboratory derivative of a common inhabitant of the human intestine-lends itself to being engineered because its genetic structure has been so well studied. In the first step of the process, scientists place the bacterium in a test tube with a detergent-like liquid. This dissolves the microbe's outer membrane, causing its DNA strands to spill...