What type of charge does the cathode have in an electrophoresis box?

In an electrophoresis setup, the cathode is the electrode that carries a negative charge. This is because during the electrophoresis process, negatively charged particles, such as DNA or RNA molecules, will migrate towards the positively charged anode. Since these molecules are attracted to the opposite charge, the cathode must be negative to draw them toward it.

Understanding the charge of the cathode is key in the context of gel electrophoresis, as it influences the movement of the charged particles through the gel medium. The migration of these molecules can be influenced by factors like their size and charge; however, the fundamental aspect that defines the cathode is that it is consistently negative in this context.

In contrast, the anode, which is the other electrode, is positively charged. The variable charge option does not apply here, as the charge on the cathode remains constant regardless of the solution used in the electrophoresis process.