Which factor does NOT affect the rate of migration in electrophoresis?

The factor that does not affect the rate of migration in electrophoresis is the color of the molecule. In electrophoresis, molecules are separated based on their physical and chemical properties, primarily their net charge, size, and the temperature of the environment in which the electrophoresis is performed.

The net charge of the molecule is crucial because charged molecules migrate towards the electrode with the opposite charge under the influence of an electric field. The size of the molecule also plays a significant role; larger molecules experience more friction and thus migrate more slowly compared to smaller molecules. Additionally, temperature can influence the viscosity of the medium and the kinetic energy of the molecules, which can ultimately affect migration rates.

However, the color of the molecule does not influence how it migrates during this process. The color is merely a property related to the absorption and reflection of light and does not impact the electrostatic or dynamic interactions that dictate migration speed in an electric field. Thus, it is not a determining factor in electrophoretic mobility.