Fleming continued his investigations, but found that cultivating Penicillium was quite difficult, and that after having grown the mould, it was even more difficult to isolate the antibiotic agent.
Fleming jätkas uurimistööd, kuid leidis, et Penicillium'i kultiveerimine on üsna raske ning pärast seene kasvatamist on antibiootikumi isoleerida raskem.