Promoter Characterization: Example of mRNA Start Site Analysis by Capillary Electrophoresis (MSACE)

Example of Promoter characterization results done at the Plant-Microbe Genomics Facility with an Applied BIosystems 3730 DNA Analyzer that measures DNA fragemtent size by automated capillary electrophoresis. The example below demonstrates how the transcription start site can be identified for a gene with this technology.

elelctropherogram of MSACE results
mRNA:  ...CAAAUGC-5'                                                                             ...UCUAUUUG-5'

For Example, the electropherogram shows the first base of a cDNA molecule (pink peaks) aligned with the corresponding sequence of the promoter region of a gene. The gene has two transcription starts at a G (black peak at positon 81) and a C (blue peak at position 126).  This work is courtesy of Massimo Merighi.