The drug works because its molecular structure matches receptors on the toxin, locking them together and inactivating the poison.

BBC: Fish food poisoning breakthrough

Despite its availability all over the world and its ease of use, the molecular structure of concrete had remained elusive for decades.

BBC: By Ian Hardy

Crick, along with James Watson and Maurice Wilkins, was given the 1962 Nobel Prize for Physiology or Medicine for "discoveries concerning the molecular structure of nucleic acids and its significance for information transfer in living material".

BBC: Francis Crick and sketch of the DNA structure

In that case the drug's molecular structure didn't match up with the branded version, changing its effectiveness.

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