Supplied in glass vials.
 
Xylene Cyanol FF (C.I. 42135) is a blue dye commonly used in laboratories for DNA and RNA gel electrophoresis. Its CAS number is 2650-17-1.
 
Xylene Cyanol FF is used as a tracking dye to monitor the progress of electrophoresis. It has a high affinity for negatively charged molecules and migrates at a similar rate to DNA fragments of 4-5 kb.