When was the scientist that  revealed by means of microscopy the previously unknown world of microorganisms born?
Antonie van Leeuwenhoek Antonie Philips van Leeuwenhoek ( , ] ; 24 October 1632 – 26 August 1723) was a Dutch businessman, scientist, and one of the notable representatives of the Golden Age of Dutch science and technology. A largely self-taught man in science, he is commonly known as "the Father of Microbiology", and often considered to be the first acknowledged microscopist and microbiologist. Van Leeuwenhoek is best known for his pioneering work in the field of microscopy and for his contributions toward the establishment of microbiology as a scientific discipline.
Kary Mullis Kary Banks Mullis (born December 28, 1944) is a Nobel Prize-winning American biochemist. In recognition of his improvement of the polymerase chain reaction (PCR) technique, he shared the 1993 Nobel Prize in Chemistry with Michael Smith and earned the Japan Prize in the same year. The process was first described by Kjell Kleppe and 1968 Nobel laureate H. Gobind Khorana, and allows the amplification of specific DNA sequences. The improvements made by Mullis allowed PCR to become a central technique in biochemistry and molecular biology, described by "The New York Times" as "highly original and significant, virtually dividing biology into the two epochs of before P.C.R. and after P.C.R."