What does gel electrophoresis separate based on?

Gel electrophoresis is a laboratory technique used to separate molecules, such as DNA, RNA, or proteins, based on their size and charge. The process involves placing samples in a gel matrix and applying an electric current. Since molecules carry an electrical charge, when the current is applied, they migrate through the gel towards the opposite charge.

Smaller molecules can move more easily through the gel's pores and therefore travel faster and further than larger molecules, leading to a size-based separation. The charge on the molecules also influences their movement; molecules with a higher charge will migrate more quickly than those with a lower charge. Consequently, this method provides a powerful way to resolve different sized and charged molecules, allowing for precise analysis and purification in various applications, such as genetic research or protein analysis.

Considering the other options, separating based on weight and color does not align with the mechanisms of gel electrophoresis, as the separation is not influenced by these properties. Temperature and solubility, as well as conductivity and polarity, also do not play roles in the separation process in the context of this specific laboratory technique. Thus, the basis of size and electrical charge is accurately represented in the correct choice.