Cresol red is a pH indicator and molecular weight marker for agarose gels. Unlike bromophenol blue and xylene cyanol, cresol red does not inhibit Taq polymerase in PCRs.
Agarose molecular weight marker
advantage: much less shadow on EtBr pictures unlike xylene cyanol and bromophenol blue
- molecular weight 404 g/mol
- in 1% agarose at ~1000 bp (between xylene cyanol and bromophenol blue)
- amber - acidic pH
- yellow - neutral
- red - alkaline