Weird profile for RNA 6000 Pico ladder

[Fel]

Hi all, I ran 2 pico chips for my RNA samples.
However, the ladders looked different each time (please see attached). Both ladders are from the same batch and they had been denatured as well.

Anyone has any idea why they differ? Do I need to denature the ladders again?

[pmiguel]

Your ladder looks okay.
You apparently added twice as much spike-in standard (the 25 nt peak) for the second run. That makes the ladder peaks look lower, but if you will note, the intensity (in Fluorescent Units) of the ladder peaks are the same.
No reason to think your results will be compromised. I suggest you declare victory and move on to the next step.

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Phillip