BIOL 205 Lecture Notes - Lecture 9: Polyacrylamide Gel Electrophoresis, Ethidium Bromide, Sybr Green I
Document Summary
What is needed: a tool to cut dna into pieces (enzymes or mechanical breakage, a means of identifying and purifying. Dna pieces of interest: enzymes : to make and manipulate dna, a means to replicate dna (so we have lots of dna to work with). What types of dna can we work with : genomic dna dna extracted from chromosomes. Needs to be cut up before use: cdna (complementary dna) What does a gene look like in a eukaryote/mammalian genome. Evolved as a defense mechanism---protect against the invasion of foreign dna. If sequences were random the distribution frequency would be: 4 base cutter = 44 = 1 cut every 256 bp. 6 base cutter= 46 = 1 cut every 4096 bp. 8 base cutter= 48 = 1 cut every 65,536. Cut dna can be separated by agarose or polyacrylamide gel electrophoresis. Fluorescent under uv light ethidium bromide intercalates between dna strands. Bac more stable than yac easier to work with.