Final answer:
To make an agarose gel for gel electrophoresis, dissolve agarose powder in a heated buffer solution, pour it into a casting tray, insert a comb to form wells, and allow the gel to cool and polymerize before removing the comb.
Step-by-step explanation:
Making an agarose gel, which is commonly used for gel electrophoresis, involves a series of steps to prepare the gel matrix that will separate DNA fragments. Firstly, an agarose and buffer solution is heated to dissolve the agarose, typically measured to create a specific concentration based on the sizes of DNA fragments to be separated. Once the agarose is fully dissolved, the hot solution is allowed to cool slightly, preventing heat damage to the gel casting tray or comb. The solution is then carefully poured into a plastic tray, ensuring no bubbles form.
While the gel is still liquid, a comb is inserted at one end to create wells, which will later serve as the loading points for DNA samples. After pouring, the agarose begins to polymerize as it cools, transitioning from a liquid into a solid gel. The comb is then gently removed, leaving behind the wells needed for sample insertion. The gel is now ready for the electrophoresis process, where DNA fragments will be separated based on size when an electric current is applied.