How to isolate a gene? There are different techniques for isolating a gene. These techniques are used to genetically modify the organism. The first step involves the selection and then isolation of the gene of interest that is to be genetically modified in an organism. It is known that most genes are transferred into the plant organism to provide tolerance to herbicides and insects. In the case of animals, genes are usually growth hormones. One of the most commonly used techniques today involves using restriction enzymes to cut DNA into fragments and then analyzing them using gel electrophoresis to separate them based on their lengths. As is known, a single strand of plant or animal DNA contains tens of thousands of genes, each working to produce a specific protein essential for the growth and survival of the organism. PCR (polymerase chain reaction) can also be used for the amplification of gene segments which can be isolated using the same procedure as gel electrophoresis. Selectable markers are used for identification and the correct size DNA band must be the one containing the gene, and it can then be excised from the gel. It takes an hour to isolate an individual gene and determine its function in a shorter time frame. Using traditional techniques to understand a single gene, the method is very time-consuming. To overcome this problem, a new procedure allowed scientists to identify specific genes in months, not years. This technique is known as transcription-based cloning. The greatest impact of this technique is on plants with large and complex genomes, including most crop species. The transcription-based cloning technique was applied specifically to the DNA of Medicago truncatula a...... middle of paper ...... establishing a symbiotic relationship with nitrogen-fixing bacteria. Using microarray gene array technology, we monitor RNA. levels produced by 10,000 genes in normal and mutant plants. "In the mutant plants, we found a gene, called DMI3, that produces extremely low levels of RNA. The normal version of the DMI3 gene produces a protein remarkably similar to proteins in tobacco plants, known to modulate their behaviors in response "This discovery led to the conclusion that the DMI3 gene could play an important role in the plant's response to calcium oscillations. It is required for rhizobial and mycorrhizal interactions and encodes a calcium- and calmodulin-dependent kinase. While working on nitrogen fixation, we discovered a general method for identifying important plant genes that is rapid and applicable to almost all plant species...