Kary Mullis - Creator of PCR Test

In 1979 Cetus Corporation hired Kary Mullis to synthesize oligonucleotides for various research and development projects throughout the company. These oligos were used as probes for screening cloned genes, as primers for DNA sequencing and cDNA synthesis, and as building blocks for gene construction. Originally synthesizing these oligos by hand, Mullis later evaluated early prototypes for automated synthesizers.
By May 1983 Mullis synthesized oligonucleotide probes for a project at Cetus to analyze a sickle cell anemia mutation. Hearing of problems with their work, Mullis proposed an alternative technique based on Sanger's DNA sequencing method. Realizing the difficulty in making the Sanger method specific to a single location in the genome, Mullis then modified the idea to add a second primer on the opposite strand. Repeated applications of polymerase could lead to a chain reaction of replication for a specific segment of the genome – PCR.
Later in 1983 Mullis began to test his idea. His first experiment did not involve thermal cycling – he hoped that the polymerase could perform continued replication on its own. Later experiments that year included repeated thermal cycling, and targeted small segments of a cloned gene. Mullis considered these experiments a success, but could not convince other researchers.
In June 1984 Cetus held its annual meeting in Monterey, California. Its scientists and consultants presented their results, and considered future projects. Mullis presented a poster on the production of oligonucleotides by his laboratory, and presented some of the results from his experiments with PCR. Only Joshua Lederberg, a Cetus consultant, showed any interest. Later at the meeting, Mullis was involved in a physical altercation with another Cetus researcher over a dispute unrelated to PCR. The other scientist left the company, and Mullis was removed as head of the oligo synthesis lab.

More info here: https://en.wikipedia.org/wiki/History_of_polymerase_chain_reaction