Chemicals to kill bacteria

1. Chemicalsto kill bacteria ‘What we need is chemicals which kill bacteria.’ ‘Yes – but they need to kill the bacteria without hurting the ill person! That’s why it took so long to find the right chemicals.’

2. The first chemicals used in the battle against bacteria were antiseptics (like the SavlonTM and GermoleneTM we use today). Antiseptics are chemicals which kill bacteria. They can’t be taken as medicine because they are poisonous to people as well as bacteria! So antiseptics are used on the outside of your body. They help to stop the spread of disease.

3. Antibiotics are chemicals which kill bacteria but don’t kill people. The first antibiotic medicine was made in 1909 from arsenic (a poison) - but the antibiotic cured people. The man who made it tried 606 different chemicals before he found one that worked!

4. In 1928 Alexander Fleming discovered penicillin, an antibiotic made by a mould. He realised the chemical he had found could kill bacteria, but it was another 10 years before it was used to make people better. It was very difficult to get the penicillin out of the mould!

5. In the 1930s Gerhard Domagk was busy looking at coloured dyes to see if they might make good medicines. He found a red dye which cured infections caused by bacteria in mice.

6. Then Gerhard Domagk’s daughter became very ill with a bacterial infection – so ill she was going to die. Dr Domagk was desperate, so he used his new dye to try and save her life. It worked and his daughter lived! The new antibiotic was called ProntosilTM. We still use this type of medicine today.

7. ‘Dr Domagk was very brave to experiment on his daughter like that, wasn’t he?’ ‘Yes – I don’t know what I’d do. She’d have died if he hadn’t tried it! And I wonder how they got penicillin to work? I’ve heard of penicillin – let’s find out more about that!’ go back to the menu