When things don't work...

So, for a while now, I've been trying to get an experiment to work. As it involves various reagents and steps, some of which can be changed, quite a few things to tweak.
So I've been changing this and that, trying it this way and that way, but nothing.

Last week, we ordered a new reagent as the old one was running out - this time a different type (producing light instead of colour).
And today - voila! It worked!
It was messy, but definitely worked!

It's quite disheartening when you try everything you can think of, only to come out with nothing. But it seems to be working now, so hopefully I can get moving with this now! - I really need to move on!

It's weird, you wait all this time for it to work, and now that it's worked I'm still thinking "Did it really work?!"...