Abdul Archive
During replacement gene therapy, we normally think of replacing the whole defective gene with a complete functional copy. However, some genetic defects consist of just a single base change, or perhaps a cluster of closely linked base alterations. In this …
Genetic engineering means that we alter an organism permanently so that the changes will be stably inherited. For multicellular organisms this implies deliberate alteration of the DNA in the germline cells. In contrast, gene therapy (occasionally called genetic surgery ) …
The polymerase chain reaction (PCR) amplifies small samples of DNA into large amounts, much as a photocopier makes many copies of one sheet of paper. The DNA is amplified using the principles of replication, that is, the DNA is replicated …
Once the gene of interest is cloned into a vector, the construct can be put back into a bacterial cell through a process called transformation. Here the “naked” DNA that was constructed in the laboratory is mixed with competent E. …
Cloning vectors are specialized plasmids (or other genetic elements) that will hold any piece of foreign DNA for further study or manipulation. The numbers and types of plasmids available for cloning have grown. In addition, other DNA elements are now …
Ultraviolet light absorption is a general method for detecting DNA, but does not distinguish between different DNA molecules. DNA can also be detected with radioactive isotopes During replication, radioactive precursors such as 32P in the form of a phosphate group …
The ability to isolate, separate, and visualize DNA fragments would be useless unless some method was available to cut the DNA into fragments of different sizes. In fact, naturally occurring restriction enzymes or restriction endonucleases are the key to making …
Gel electrophoresis followed by staining with ethidium bromide is used to separate DNA fragments by size . The gel of gel electrophoresis consists of agarose , a polysaccharide extracted from seaweed that behaves like gelatin. Agarose is a powder that …
Basic to all biotechnology research is the ability to manipulate DNA. First and foremost for recombinant DNA work, researchers need a method to isolate DNA from different organisms. Isolating DNA from bacteria is the easiest procedure because bacterial cells have …
Observed and Expected Ratios: When two individuals of known genotype are crossed, we expect certain ratios of genotypes and phenotypes in the progeny; these expected ratios are based on the Mendelian principles of segregation, independent assortment, and dominance. The ratios …