"Mass failure"

For the past couple weeks in nucleic acids lab, we've purified RNA from mouse brain slices, converted it to cDNA, then ran a PCR to amplify and isolate specific genes, with each student having a different gene. Today was supposed to be the moment of truth: run an agarose gel and visualize the DNA bands in UV light to see if everything else had worked properly.

My bench was the first group in the dark room...nothing. We had smears (contamination?) in a couple lanes and one very faint band near the top of the gel, but it was clearly too large to be what we were looking for. This seemed strange: you would think that maybe one person would have messed up, or a pair working together, but not all 4 (this is supposed to be an advanced bio lab, after all).

On to the next group...nothing. Group 3...nothing.
And so on and so forth, until all the groups had gone to the dark room and returned with disappointing photos of our gels.

The obvious conclusion: Something was wrong with everyone's procedure, so not a technique mess-up, but perhaps an incorrect buffer, using the wrong temperature during PCR, etc. Now the question is what went wrong, aka do we have to start all over again, and if not, where do we start again?

While we were all happy to get out of lab relatively early, we all still felt bad for Professor Nelson: "I've never had a mass failure like this before..." Just goes to show the "real" truth of science: Nothing ever goes quite as you expect it to =P