Last week, our proteomic group did a 2D of a purified protein but, unfortunately, it seemed we had a contamination. So, this week-end, we performed blank tests in order to see if the contamination came from our experiment (or from the purification). We tested our fluorescent markers and different 1D strip holders. At a normal gain, the image looks fine: contamination doesn’t come from the 2D
But when I increase the gain, the image (and thus our gel) is really contaminated! We really have to look where did the contamination happen! Look at this:
In France the person fooled is known as poisson d’avril. This has been explained as arising from the fact that in April the sun quits the zodiacal sign of the fish. The French traditionally celebrated this holiday by placing dead fish on the backs of friends. Today the fish has been replaced with paper cut-out.
(Explanation from Wikipedia)