Bioanalyzer, empty wells show profiles.

[Spleen]

Dear All.
It has occurred in the last couple of run that empty wells in the bioanalyzer actually showed a RNA profile (indistinguishable from a real sample)
Here some details:
-RNA pico chip
-It occurred 3 times (weeks apart) every time in a different well.
-I run a test with only empty wells and one positive control in the central well, there was no contamination.
-The "ghost samples" in one case was very similar to a real sample even though these were not adjoin (well 6 and 10 ).

Has anyone experienced anything like that before that could not be due to a mis-pipetting ( even though I can imagine a mis-pipetting I really don't think so) ?

Thank you very much and have a good day!

[pmiguel]

Dear All.
It has occurred in the last couple of run that empty wells in the bioanalyzer actually showed a RNA profile (indistinguishable from a real sample)
Here some details:
-RNA pico chip
-It occurred 3 times (weeks apart) every time in a different well.
-I run a test with only empty wells and one positive control in the central well, there was no contamination.
-The "ghost samples" in one case was very similar to a real sample even though these were not adjoin (well 6 and 10 ).

Has anyone experienced anything like that before that could not be due to a mis-pipetting ( even though I can imagine a mis-pipetting I really don't think so) ?

Thank you very much and have a good day!

If you used the same electrode for a nano-RNA chip prior to running a pico-RNA chip then the pins would need to be very carefully washed. The amount of RNA needed to visualize on a pico-RNA chip is very small.

--
Phillip

[sajoshi]

Clean the pins with a brush. Alternate with propanol and milliq water a few times and try again.