Historical Highlight: The Chemical Characterization of the Pneumococcal Transforming Principle

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Neil S. Greenspan


This article is an updated version. See Erratum: doi: 10.20411/pai.v9i1.704

The editors of Pathogens and Immunity are commemorating this month, the 80th anniversary of the publication of the landmark article by Oswald Avery, Colin MacLeod, and Maclyn McCarty in the Journal of Experimental Medicine on February 1, 1944 [1]. The study by Avery et al determined with extraordinary rigor the chemical nature of the so-called transforming principle inferred to exist by Frederick Griffith based on experiments he published in 1928. 


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Author Biography

Neil S. Greenspan, Case Western Reserve University, Cleveland, Ohio

Dr. Neil Greenspan received his A.B., magna cum laude, in Biochemical Sciences from Harvard College in 1975. He then earned M.D. and Ph.D. (Immunology) degrees at the University of Pennsylvania. From 1981 until 1986, Dr. Greenspan was a Resident in Laboratory Medicine (Clinical Pathology) at Barnes Hospital, and from 1982-1985 he was a Postdoctoral Fellow in Molecular Immunology at Washington University, both in St. Louis. In 1986, Dr. Greenspan became a faculty member at the Case School of Medicine. He is currently Professor of Pathology at Case and the Director of the Histocompatibility and Immunogenetics Laboratory at University Hospitals Cleveland Medical Center.


1. Avery OT, Macleod CM, McCarty M. Studies on the Chemical Nature of the Substance Inducing Transformation of Pneumococcal Types : Induction of Transformation by a Desoxyribonucleic Acid Fraction Isolated from Pneumococcus Type III. J Exp Med. 1944;79(2):137-58. doi: 10.1084/jem.79.2.137. PubMed PMID: 19871359; PMCID: PMC2135445.

DOI: https://doi.org/10.1084/jem.79.2.137