To fit such a long molecule within the tiny space ... Histones carry a slight positive charge, and DNA carries a slight negative charge. Since opposite charges attract, the DNA is pulled in ...

This means that a small DNA molecule will travel a greater distance ... the gel has a positive charge and the other end has a negative charge. Because DNA and RNA are negatively charged molecules ...

These bases are the rungs of the DNA ladder. (It takes two bases to form a rung -- one for each side of the ladder.) A sugar molecule, a base, and a phosphate molecule group together to make up a ...