Si's Cycle 300 miles in September

£25 could either buy 500 plastic test tubes, 5 boxes of gloves, 5 beakers, or a Bunsen burner, which are the understated tools of many experiments.

£50 can pay for chemicals called restriction enzymes, which cut long strands of DNA, allowing scientists to find out more about the genes that cause cancer.

Early diagnosis is essential to getting the right treatment to people with cancer. £100 could pay for a cancer biopsy, where a tiny amount of a lump is removed and sent to be studied in a lab.

£150 could fund a team of researchers in Manchester for half a day. They're trying to diagnose and monitor lung cancer in a less invasive way.

£200 can buy DNA nucleotides, something scientists use to make copies of genes, giving us clues about how things go wrong in cancer.