Johann Freiderich Meischer
First to isolate and identify nucleic acid.
Did this by treating cells with pepsin, a molecule from pig stomach, and then he recovered nuclein.
Discovered transformation in pneumonia-causing bacteria. (in vivo)
Sia & Dawson
developed a method of transforming bacteria in vitro
Avery, MacLeod and McCarty
Purified various types of molecules from heat-killed pathogenic bacteria, and tried to transform live nonpathogenic bacteria with each type (carbohydrates, lipids, protein, etc.) Only DNA worked.
This proved that the transformation factor that Griffith discovered was actually DNA, so that DNA is the hereditary material.
Hershey & Chase
Used radioactive material to label DNA and protein; infected bacteriophage with these labels and helped prove that DNA is the genetic material, not proteins
His most noted research was on the tobacco mosaic virus. He discovered that the genetic control of viral reproduction was RNA and that it is carried in the nucleic core of each virus
developed Chargaff's rules:
G = C
A = T
Used x-ray diffraction and x-ray crystallography to see the double-helix structure of DNA
Kavenoff, Klotz, & Zimm
Proved/discovered that a chromosome contains a single molecule of DNA
carried out the X-ray crystallography analysis and photography of DNA. this provided Watson & Crick with key information about DNA's structure.
Watson & Crick
discovered double-helix structure of B-DNA.
Meselson & Stahl
Showed that E. Coli chromosomes replicate semiconservatively, using equilibrium density-gradient centrifugation.
Taylor, Woods, & Hughes
first showed semiconservative replication of eukaryotic chromosomes with Vicia faba. (roots of beans). Determined structure of replicating bacteria using autoradiography.
Showed that the E. Coli chromosome is a single duplex of DNA.
Schnos & Inman
Showed that the gamma chromosome in bacteriophage gamma replicates bidirectionally and is initiated at a unique origin.
first to photograph transcription process, and his photographs later helped scientists understand how RNA is turned into protein
Scientist who discovered the fragments that grow from lagging strands
Blackburn & Greider
discovered how chromosomes are protected by telomeres and telomerase
also helped discover how telomeres protect chromosomes, and created the first artifical yeast chromosome
1964, revealed the triplet nature of the genetic code
was the first to define the base sequence of a complete mammalian gene
Identified RNA Polymerase IIB
utilized gene cloning and sequencing technology to first decipher the structure of eukaryotic genes and their modes of regulation
worked on the primary actions of steroid hormones and nuclear receptors. considered 'father of molecular endocrinology'
Alan Jefferies & Richard Flavell
DNA fingerprinting, introduced using DNA analysis for forensic science
one of the founders of modern molecular cloning
Oscar Miller & Barbara Hamkalo
prepared an electron micrograph showing coupled transcription & translation in an E.Coli gene
discovered that RNA could cut itself strands of RNA, possibly meaning that life started out as RNA
helped Thomas Cech analyze the ribozyme, RNAse P, which led to the discovery that RNA is itself catalytic
Herrick and Irons
observed the first sickle-cell anemia patients
Tate & Beadle
demonstrated that one gene = one polypeptide
established that gene sequences and protein sequences are colinear
studied the ribosome by disassembling and assembling the ribosome into its subunits
also demonstrated that the 70S ribosome that was formed by association of the 30S and 50S subunits could not directly enter into protein synthesis; the initiation of protein synthesis was a stepwise process in which the messenger RNA first formed a complex with a 30S subunit and an initiator transfer-RNA; only after that complex formed could the 50S subunit enter into the complex
discovered the 'Kozak' consensus sequence, (gcc)gccRccAUGG
plays a major role in the initiation of translation