isolated nucleic acids calling them nuclein (A,C,G,T)

could this be genetic material or is it made up of the much more complicated protiens?

worked with mice

discovered non-virulent rough strains of Diplococcus pneumonia bacteria are transformed to smoothness and virulence by mixing with dead smooth virulent bacteria

which biochemical component is responsible?

use bacterial transfromation (from Griffith mice) as an assay to demonstrate that the transforming biochemical is DNA, hence DNA must be genetic material

True for all organisms?

confirm Avery by radioactively labeling the proteins of bacteriophage with 35sulfur isotope and their DNA with 32phosphorus and show that only DNA enters teh bacterial cell

what is DNA beyond ACGT?

accumulates enough evidence from chemical anaylsis of many organisms to say that the proportions of A=T and G=C

how do they fit together?

use X-ray crysallography to show that the DNA strand is long, thin and of uniform diameter, 2nm, has repeating structures every .34 and 3.4nm and might be a helix

what does DNA look like all together?

developed a wire and cardboard cutout models eventually settling on a right hand double helix structure, the ribose-phosphate backbones on the outside and the base on the inside with A hydrogen bonding to T and G to C

A to T is 2 hydrogen bonds

G to C is 3 hydrogen bonds

californians Herbert Boyer and Stanley

mid 1970s

stanford university invented cloning of pieces of DNA

led to the explosion of research in molecular biology and to the ability to modify the genetic makeup of animals and other organisms

DNA senuencing published

also invented protein sequencing