I recently sent samples to an establishment for sequencing. I sent the maximum concentration of DNA that was advised for the sample type (500 ng; plasmid, miniprep). My sequences all came back with weak signals (generally 100-200 signal intensity). I sent the samples again, this time increasing the DNA concentration beyond the advised concentration. Where I sent twice the amount of DNA, signal intensity increased five-fold and a three-fold increase in DNA gave a nine-fold increase in signal. Is that non-linear response normal, or should I try sequencing elsewhere?
BTW, the DNA was quantified both on the NanoDrop and by densitometry, against a size-marker (the densitometry gave somewhat higher values - the NanoDrop values were used to calculate DNA to be sent).
Edited by seanspotatobusiness, 26 April 2011 - 03:40 AM.