BIO372H5 Lecture Notes - Lecture 4: Ethidium Bromide, Nucleic Acid Thermodynamics, Gc-Content
Document Summary
Dna denaturation (can be melted): double strand to single strand dna - absorbance increases, then the dna will reform the double strand. Chemicals (e. g. formamide): formamide will compete with h bonding within the duplex and this will cause denaturation. High ph: the oh groups will h bond with dna single stranded to hydrolization, absorbance increases even further b/c randomness is higher. Length of dna (for short fragments) - only applies to short fragments. Base composition - the more g-c the tighter the bond is, the harder the dna is to melt. The slopes are different: due to variance in g-c content, green melts less sharper than blue curve. A straight line, the further down tm is the lower g-c content is. Water = 1g/ml, dna is denser than water. Cesium chloride, a salt, heavy atom, a solution of this in a tube is place in high speed centrifuge in.
