Fleming published his findings on penicillin in the "British Journal of Experimental Pathology". However, he faced difficulties in isolating and purifying the penicillin in sufficient quantities for further research and clinical trials.

Fleming and his colleagues attempted to isolate and purify penicillin, but they encountered significant challenges. The process was complex and yielded only small quantities of the unstable substance. While they conducted some preliminary tests, further research stalled.

The potential of penicillin was largely overlooked until a team at the University of Oxford, led by Howard Florey and Ernst Chain, became interested in it in the late 1930s. They saw the potential of penicillin as a powerful antibacterial agent and developed methods for its large-scale production.

Florey and Chain published a paper demonstrating the remarkable effectiveness of penicillin in treating bacterial infections in mice. This publication sparked intense interest in penicillin and paved the way for its development as a life-saving drug.

The Oxford team conducted the first clinical trials of penicillin on human patients. The results were dramatic, demonstrating penicillin's ability to cure severe bacterial infections that had previously been untreatable. These trials marked a turning point in medicine.