SSC buffer is used to ensure a seal and prevent drying of the gel. Buffer transfer by capillary action from a region of high water potential to a region of low water potential (usually filter paper and paper tissues) is then used to move the DNA from the gel onto the membrane; ion exchange interactions bind the DNA to the membrane due to the negative charge of the DNA and positive charge of the membrane. Five methods can be used to transfer DNA fragments to the solid membrane and they are: 1. Upward capillary transfer: This method transfers the DNA fragment upward from the gel to the membrane where the flow of the liquid or the buffer will be upward, 2. Downward capillary transfer: This method is done by placing the gel on the surface of the membrane (usually nylon charged membrane) and the DNA fragments will be transferred in a downward direction with the flow of the alkaline buffer, 3.Simultaneous transfer to two membranes: This method is used to transfer DNA fragments of high concentration simultaneously from the gel to two membranes, 4. Electrophoretic transfer: This method usually uses large electric current which makes it difficult to transfer the DNA efficiently due to the temperature of the buffer used, so these machines can be either equipped with cooling machines or used in a cold area, 5. Vacuum transfer: This method uses a buffer from the upper chamber to transfer the DNA from the gel to the nitrocellulose or nylon membrane, the gel is placed directly on the membrane, and the membrane is placed on a porous screen on the vacuum chamber. Immobilization: The membrane is then baked in a vacuum or regular oven at 80 °C for 2 hours (standard conditions; nitrocellulose or nylon membrane) or exposed to ultraviolet radiation (nylon membrane) to permanently attach the transferred DNA to the membrane. Hybridization: After that, a hybridization probe—a single DNA fragment with a particular sequence whose presence in the target DNA is to be ascertained—is exposed to the membrane. The probe DNA is labelled so that it can be detected, usually by incorporating radioactivity or tagging the molecule with a fluorescent or chromogenic dye. In some cases, the hybridization probe may be made from RNA, rather than DNA. To ensure the specificity of the binding of the probe to the sample DNA, most common hybridization methods use salmon or herring