Relative absorbance 260 nm 1 3 1 2

Relative absorbance (260 nm) 1. 3 1. 2 1. 0 50 Tm 1. 1 70 90 Temperature (C) Adapted from Voet et al (1999) Fundamental of Biochemistry p. 739 Denaturation of DNA Causes Hyperchromism

1. 4 Pneumococcus (38%) G+C E. coli (52%) S. Marcescens (58%) 1. 2 M. Phlei (66%) 1. 0 70 80 90 Temperature (C) 100 Adapted from Garrett & Grisham (1999) Biochemistry (2 e) p. 372 Relative absorbance (260 nm) G+C Content Is Proportional to Tm

Cation Neutralizes Phosphate and Elevates Tm 100 G + C (%) 80 0. 01 M phosphate 0. 001 M EDTA 5’ 3’ 60 40 0. 15 M Na. Cl 0. 015 M Na citrate 20 0 5’ 60 70 80 90 100 3’ 110 Tm (C) Adapted from Garrett & Grisham (1999) Biochemistry (2 e) p. 372

G+C Content Is Proportional to DNA Density M. phlei Serratia 60 40 20 1. 69 E. coli Calf thymus Salmon sperm Pneumococcus 1. 70 1. 71 1. 72 Density (r) 1. 73 1. 74 Adapted from Garrett & Grisham (1999) Biochemistry (2 e) p. 375 G + C (%) 80

Renaturation Time Is Proportional to Complexity Genome size 1 10 102 103 104 105 106 107 108 109 1010 Fraction reassociated 0 0. 5 Poly U/ Poly A Mouse satellite MS 2 T 4 E. coli Calf 1. 0 10 -6 10 -5 10 -4 10 -3 10 -2 10 -1 1 10 100 1 K 10 K c 0 t (mole/L • sec) Time for renaturaton (Longer) Adapted from Garrett & Grisham (1999) Biochemistry (2 e) p. 374