Behind every dashing scientific hero and stereotyped eureka moment is an entire universe of reality that fails to make it into the undergraduate textbooks. It seems to be human nature to ascribe discovery to one person, distilling its essence to a figurehead who is then fated to symbolize, in popular imagination, a process that often takes many years, and numerous people, to achieve. It may not be fair, but it certainly is expedient.

So it is with the discovery and development of penicillin. If you mention it to your average educated person and ask what comes to mind, you will probably get back the name Alexander Fleming, and a quaint story about a serendipitous accident involving a disheveled Petri dish and a moment of shrewd observation. I confess I would have answered no differently before I sat down to watch Breaking the Mould: The Story of Penicillin (BBC 4), a fictionalized account of the process by which penicillin was elevated from chance observation to a wonder drug that saved millions of lives in the dreg-ends of the Second World War and beyond.

The Petri dish was, of course, only the beginning. Although Fleming published the result in 1929, he was unable to extract enough of the unstable active agent to take it any further, and eventually moved on to other challenges. It was only in 1938 when his paper caught the eye of a team of researchers at the Nunn School of Pathology in Oxford, led by Professor Howard Florey (Dominic West), that things really started to move.

In the drama, Florey is portrayed as a solid, dedicated scientist with a passion for doing something truly useful for the new war effort – to the point that he has to go behind the Medical Research Council’s back to assemble and fund his crack antibiotics team.

‘Useful’ is a bit of an understatement. One of the strong points of this film is the simple but graphic way it portrays just how lethal bacteria can be, and how often such outcomes occurred in a world without antibiotics. In one scene, we are shown a robust young man picking roses for his wife; after a simple scratch with a thorn, he ends up dying a horrible death from septicemia. You feel Florey’s pain and frustration as his team painstakingly produces precious milligrams of the substance, but can’t interest the MRC or any big pharma to scale up the production as thousands of soldiers and civilians lay dying in isolation wards.

The science in this film is excellent, and an unusually large fraction of the story is devoted to lab scenes. We start with Florey and chemist Ernst Chain (Oliver Dimsdale) bandying about Fleming’s paper as a crazy idea they might work on; we see Florey cajoling a team to join his project despite its patent unpopularity with upper management; we see Florey suffer grant rejection after rejection. We watch Chain, and his colleague Norman Heatly (Joe Armstrong), working late into the night struggling to extract the fickle compound, cobbling together ever more convoluted contraptions – at various points, their machinery involves cake tins, bed pans, rubbish bins and even entire bathtubs. The first animal trial is lavishly described with two test groups and two control groups (and informative dialogue to a refreshing minimum – Florey doesn’t explain what a ‘control’ is – his actions make it obvious). We are made to wait for the result – no instant successes. The human trials are similarly realistic – two patients die before the tricky drug dosage is finally worked out.

The scientific profession is also richly and realistically portrayed. These scientists are obviously human, and have great and diverse personal appeal. There is even a female scientist, Margaret Jennings (Kate Fleetwood), in the team – in place even before the outbreak of the war made such stints much more common. And we are treated to the human stresses and strains of normal scientific interactions – disputes about patenting and credit in particular. The lab, too, is beautifully shot – the glassware, the mould cultures, even the mice, all suffused with a golden hue of nostalgia.

This was, of course, a work of fiction based on real-life people and events. So was it accurate? Florey’s supposedly heartfelt passion for saving lives was probably grossly trumped up to make his character more appealing. He is in fact on record as saying:

I don’t think it ever crossed our minds about suffering humanity. This was an interesting scientific exercise, and because it was of some use in medicine is very gratifying, but this was not the reason that we started working on it.

And there might be the opposite problem with Fleming, who is portrayed (in a chillingly vague and diffident star performance by Denis Lawson) as a credit-stealing egomaniac with about as much charm as one of his mould cultures. Other sources, however, have reported that Fleming downplayed his role in the penicillin story, even calling his own fame “the Fleming Myth". The truth, as always, probably lies somewhere in between.

Related information

Breaking the Mould: The Story of Penicillin will be available to the UK and other eligible countries via the BBC iPlayer service until Wednesday evening, 5 August.