Question: what kind of chemicals are there

Sarah Thomas answered on 22 Jun 2011:

This is a really hard question!! Because there are more kinds of chemicals than I could possibly imagine!!

Ok I’m going to describe to you the types of chemicals that I use most often.

So as you might have seen on my profile, I am trying to make a blood test for cancer to help doctors diagnose patients that have cancer much faster, to get it caught in the early stages while the patient still has a good chance of survival.

I use a lot of acids and bases, probably just like you at school. Acids and bases and pH is really important and you have to get it right to make certain reactions work. I make solutions that we call buffers. The job of a buffer is to maintain the pH at a constant level no matter what you put in it. The buffer kind of mimics a biological system, you’re body is constantly balancing itself and maintain pH. The pH of your blood only varies between 7.35 and 7.45 no matter what your body goes through.

I also use a chemical called hydrazine, which is really dangerous! Hydrazine has the chemical formula N2H4. It is highly toxic and extremely unstable! This means I have to be super careful when handling it, and wearing all my safety gear. Once I am finished with my experiment, I have to neutralise the hydrazine with bleach. Anything that has come into contact with the hydrazine but be neutralised: my gloves, any glassware or pipettes I have been using. When the hydrazine reacts with the bleach, it bubbles furiously and makes this big foam. Even just one tiny drop will do that!

I also use chemicals that are fluorescent. This is because I am trying to make a dye that will become fluorescent in the presence of cancer signals in the patients blood – that is how the blood test will work. The dye is actually made of 3 parts. It is a sugar that has 2 different dyes attached to it. When the 3 parts are intact there is no fluorescence. They kind of cancel each other out. When it comes into contact with the cancer signals in the patients blood, the sugar breaks in two and then you see fluorescence.

It may sound strange that i’m attaching the dyes onto a sugar but I discovered last year that it’s the sugar that recognises the cancer signals and it does this thing where is splits in two. That’s when I came up with the idea for the blood test.

Sorry if this is not a great answer to your question! Please add a comment or ask me another one if you’re not happy with my answer! I kind of rambled a bit!!