二甲苯蓝(xylene cyanol)又称二甲苯青，可以被用于作为琼脂糖凝胶电泳和聚丙烯酰胺凝胶电泳的标记物，相似的，溴酚蓝和橙黄G也可以用于该用途。

在1%的凝胶中，二甲苯蓝以4000个DNA碱基对的速率迁移。

Xylene cyanol can be used as a color marker, or tracking dye, to monitor the process of agarose gel electrophoresis and polyacrylamide gel electrophoresis. Bromophenol blue and orange G can also be used for this purpose.

Once mixed with the sample, concentration of xylene cyanol is typically about 0.005% to 0.03%.