Hemprich lectured at Berlin University on comparative physiology, and wrote Grundriss der Naturgeschichte (Compendium of Natural History) (1820).
In 1820 Hemprich and Ehrenberg were invited to serve as naturalists on a primarily archeological expedition to Egypt, led by Prussian General von Minutoli.
In 1823 Hemprich and Ehrenberg sailed across the Gulf of Suez to El Tur on the south-west coast of the Sinai peninsula, remaining there for nine months.
During this time they visited Mount Sinai, and Ehrenberg became one of the first naturalists to study the marine life of the Red Sea.
Ehrenberg travelled back to Europe, and in 1828 published an account of their discoveries, under both their names, entitled Symbolae Physicae.