How to isolate a gene?There are different techniques for isolating a gene. These techniques are used to genetically engineer the organism. The first step involves the selection and then the isolation of the gene of interest that must be genetically engineered into an organism. It is known that most of the 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 common techniques used to date is to use restriction enzymes to cut DNA into fragments and then perform gel electrophoresis for separation based on their length. As we know, a single strand of plant DNA or animal DNA contains tens of thousands of genes, each of which works 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 that can be isolated using the same procedure as gel electrophoresis. Selectable markers are used for identification and the DNA band of the correct size should be the one containing the gene and can therefore be excised from the gel. It takes an hour to isolate a single gene and determine its function in a shorter time frame. Using traditional techniques to target just one gene is a time-consuming method. To overcome this problem, a new procedure that allowed scientists to identify specific genes in a matter of months, not years. This technique is known as transcription-based cloning. The greatest impact of this technique is on plants with large, complex genomes, including most crop species. The transcription-based cloning technique was specifically applied to the DNA of Medicago truncatula in ...... middle of paper ...... a symbiotic relationship with nitrogen-fixing bacteria. Using microarray gene chip technology, we monitor the RNA levels produced by 10,000 genes in both 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 that is remarkably similar to tobacco plant proteins, known to modulate their behaviors in response to football." This discovery led to the conclusion that the DMI3 gene may play an important role in the plant's response to calcium oscillations. It is required for rhizobial and mycorrhizal interactions and encodes a calcium- andcalmodulin-dependent kinase. In the process of nitrogen fixation, we have discovered a general method for identifying important plant genes that is rapid and applicable to almost all plant species.