The purpose of this experiment was to isolate the recombinant plasmid. First, a bacteria and DNA were mixed together by cold calcium chloride with a heat shock, ending at a cold temperature. In this process, the bacteria has no choice but to take up the plasmid DNA. Then the bacteria and DNA was spread over a culture plate containing two antibiotics: tetracycline and kanamycin. The transformed bacteria with both resistance genes are the only ones that can only grow in the presence of both antibiotics. The result of this experiment was a bacteria transformed that contained a recombined plasmid with both tetracycline and kanamycin genes. Not only this, but also the bacteria could’ve also doubly transformed. The scientists had seen that the bacteria had been transformed by a recombinant plasmid.
In bacterial transformation, in order to grow, the bacteria had to be resistant to both tetracycline and kanamycin antibiotics. In order to grow, the bacteria had to take in both genes in order to be resistant and grow. In bacterial transduction, the cell membrane is made up of lipid molecules with negatively charged phosphates. Because it is so negatively charged, the DNA helix is repelled by the lipids. In order for the DNA helix to pass through, the CA2+ ions create a neutral situation, and with the help of a heat shock and cold temperatures, the CA2+ and lipid molecules do not repel as much. The heat shock may set up a current and with the ionic shield in place, the DNA passes through the adhesion zone.
Source: http://www.dnalc.org/view/15916-DNA-transformation.html
No comments:
Post a Comment