In the Hebrew Bible and the Qur'an, Aaron ( /ˈærən/ or /ˈɛərən/;Hebrew: אַהֲרֹן‎ Ahărōn, Arabic: هارون‎ Hārūn, Greek (Septuagint): Ααρών ), who is often called "'Aaron the Priest"' (אֵהֲרֹן הֵכֹּהֵן) and once Aaron the Levite (אַהֲרֹן הַלֵּוִי) (Exodus 4:14), was the older brother of Moses, (Exodus 6:16-20, 7:7; Qur'an 28:34) and a prophet of God. He represented the priestly functions of his tribe, becoming the first High Priest of the Israelites. While Moses was receiving his education at the Egyptian royal court, and during his exile among the Midianites, Aaron and his sister Miriam remained with their kinsmen in the eastern border-land of Egypt (Goshen). There, Aaron gained a name for eloquent and persuasive speech, so that when the time came for the demand upon the Pharaoh to release Israel from captivity, Aaron became his brother’s nabi, or spokesman, to his own people (Exodus 7:1) and, after their unwillingness to hear, to the Pharaoh himself (Exodus 7:9). Various dates for his life have been proposed, ranging from approximately 1600 to 1200 BC.

Sir Aaron Klug, OM, PRS (born 11 August 1926) is a Lithuanian-born British chemist and biophysicist, and winner of the 1982 Nobel Prize in Chemistry for his development of crystallographic electron microscopy and his structural elucidation of biologically important nucleic acid-protein complexes.

Klug was born in Želva, Lithuania to Jewish parents Lazar and Bella (née Silin) Klug with whom he moved to South Africa at the age of two. He later graduated with a degree in science at the University of Witwatersrand and studied crystallography at the University of Cape Town before moving to England, completing his doctorate at Trinity College, Cambridge in 1953.

He moved to Birkbeck College in the University of London in late 1953, and started working with Rosalind Franklin in John Bernal's lab. This experience aroused a lifelong interest in the study of viruses, and during his time there he made discoveries in the structure of the tobacco mosaic virus. In 1962 he moved to the newly built MRC Laboratory of Molecular Biology in Cambridge. Over the following decade Klug used methods from X-ray diffraction, microscopy and structural modelling to develop crystallographic electron microscopy in which a sequence of two-dimensional images of crystals taken from different angles are combined to produce three-dimensional images of the target.