1% means that the concentration of agarose in agarose gel electrophoresis is 1%.

Agarose gel electrophoresis is a commonly used method to separate and analyze biological macromolecules, such as DNA, RNA and protein. Where 1% means that the concentration of agarose is 1%. Agarose is a polysaccharide, which can form a gel-like matrix and be used to separate biological macromolecules.