Cresol Red
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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 5000bp and bromophenol blue 500bp)
- in 3% agarose at >100bp (xylene cyanol 300bp)
pH indicator
- amber - acidic pH
- yellow - neutral
- red - alkaline