Lister continued to develop improved methods of antisepsis and asepsis when he realised that infection could be better avoided by preventing bacteria from getting into wounds in the first place. This led to the rise of sterile surgery. Lister instructed surgeons under his responsibility to wear clean gloves and wash their hands in 5% carbolic solution before and after operations, and had surgical instruments washed in the same solution. He also introduced the steam steriliser to sterilize equipment. His discoveries paved the way for a dramatic expansion to the capabilities of the surgeon; for his contributions he is often regarded as the father of modern surgery. These three crucial advances - the adoption of a scientific methodology toward surgical operations, the use of anaesthetic and the introduction of sterilised equipment - laid the groundwork for the modern invasive surgical techniques of today.