Biological Techniques :: essays research papers

1. (a) I. Plasmids be important tools in molecular biology. Plasmids are small circular deoxyribonucleic acid that has the ability to acquiesce and replicate in bacterial cells and can be used as vectors to introduce foreign genes into bacteria for cloning and sequencing. Any gene must(prenominal) be inserted into an appropriate location of a plasmid to be expressed. The richness of a plasmid is in the step of cloning and sequencing when the construction of a recombinant desoxyribonucleic acid molecule occurs. The target gene fragment is ligated to a plasmid, and becomes recombinant DNA. indeed the plasmid can replicate autonomously in an appropriate host organism.II. The polymerase chemical chain reaction (PCR) is the amplification of DNA sequence by repeated cycles of cosmic string seperation and replication. This is a direct method of making copies of a desired DNA sequence, un manage the technique utilise plasmids. PCR is a process quite like DNA replication. It is stil l the process of two DNA strands unwinding, replicating, and then reannealing, thus far the strands are unconnected by heat. Generally temperatures must be change magnitude to 94-96 degrees C for the hydrogen bonds to break and the separation to occur. Once the stands are separated they can be used as templates for complementary strands to be synthesized by DNA primers. After the strands are completely synthesized, the temperatures are brought back worst to 50-65 degrees C for the primers to anneal with the template DNA, and a DNA polymerase can hit complementary strands use free nucleotides that have been added to the solution.III. Restriction fragment length polymorphism (RFLP) analysis is a technique in which DNA regions are digested using restriction endonucleases, and subjected to radioactive complementary DNA probes to compare the differences in DNA fragment lengths between individuals. The DNA in question is digested using restriction endonuclease(s). The DNA is then r un on a change and appears to be very long. The gel is subject to a chemical that causes the double-stranded DNA to separate into to individual strands. The strands are then transferred to a nylon membrane with using an electric current, where it will bind. The transfer process is called Southern blotting.