Question: what does 2,2,5,5-tetramethylpyrrolinoxyl hydrazide do?

Sarah Thomas answered on 17 Mar 2011:

Ok 2,2,5,5-tetramethylpyrrolinoxyl hydrazide – i’m going to call that TMPO for short.

TMPO is something called a spin label. This means that it has an unpaired electron on it. Have you learnt at school that electrons prefer to pair up? It’s quite hard to make a spin label for that reason!

Now, the dye I have made will bind to cancer chemicals in the blood, right? Well I thought it might be interesting to look and see how the binding works. Like what shapes have to fit together for the dye and the cancer chemical to join. Well that is really hard to do! But if I can attach a spin label onto my dye, the unpaired electron does something really special when you put it under a massive magnet and it will help us figure out how the binding works.

This could be a really important experiment, because if we know what shapes fit into the cancer chemicals, we can try and make a drug that will fit that shape. The drug could bind to the cancer chemicals and block them so the cancer couldn’t grow anymore. Lots of drugs work in this way, like you have to find the shape that fits, then make a drug that is that shape and then it can block the thing that is making the patient sick.