Philipp Holliger is a Swiss molecular biologist best known for his work on xeno nucleic acids (XNAs)[1] and RNA engineering.

[5][6] While in the Winter laboratory, Holliger developed a new type of bispecific antibody fragment, called a diabody and worked on elucidating the infection pathway of filamentous bacteriophages.

[7][8] After he became an independent group leader at the MRC LMB, Holliger shifted his research focus towards synthetic biology, where he developed methods for emulsion-PCR and in vitro evolution.

[16] More recently, he described the first polymerase ribozyme that can use nucleotide triplets to copy highly structured RNA templates[17] including segments of itself.

[18] He also discovered that the steep concentration and temperature gradients resulting from freeze-thaw cycles could be harnessed to drive ribozyme assembly and folding, acting akin to chaperones in modern biology.