Kossel, Albrecht (1853-1927) was a German biochemist and pioneer in using methods of organic chemistry to study physiology, particularly that of tissues and cells. He received the 1910 Nobel Prize in in physiology or medicine for his work on proteins and cell chemistry.

Ludwig Karl Martin Leonhard Albrecht Kossel was born Sept. 16, 1853, in Rostock, Germany. Although he received his M.D. degree from the University of Strasbourg in 1878, he decided to pursue a career in biochemistry after meeting Ernst Felix Immanuel Hoppe-Seyler, one of the most prominent scientists in that newly emerging field. While working as an assistant in Hoppe-Seyler's lab at Strasbourg's Institute of Physical Chemistry, from 1877 through 1881, Kossel began to study the composition of the cell's nucleus, focusing on nuclein, a substance now known as nucleoprotein.

Nuclein had already been discovered, but Kossel managed to break it down and in doing so discovered it had two distinct parts, one being protein and the other not. The nonprotein part, called “nucleic acid,” was a substance whose makeup was unlike any other natural product then known. Kossel then discovered that further breakdown of the nucleic acid resulted in the production of carbohydrates and the nitrogen-bearing compounds “purines” and “pyrimidines.” Of these, he isolated the purines “guanine” and “adenine” and the pyrimidines “thymine” (which he was the first to isolate), “uracil,” and “cytosine.”

Kossel pushed his knowledge of chemistry to reveal its significance to actual biological processes. He did this with nuclein, rightly suspecting that it was involved in the development of flesh tissue. His discoveries were early foundation points upon which later investigations of nucleic acids have been undertaken, especially their role in storing and transmitting genetic data. In the 1890's, Kossel focused his research on proteins and discovered the amino acid “histidine,” one of the primary components of protein.