Gel Electrophoresis |

separation of strands of DNA of different lengths
analysis of proteins and DNA
place mixture of molecules into wells cut in agarose gel and apply electric field
factors affecting movement speed of molecules:

separates polypeptides produced by different alleles of many genes
charge on protein is dependent on the ionization of the R groups on the amino acid residues
charge depends on pH hence use of buffer solution to keep constant pH
polypeptides separate due to different net charges
proteins are usually negatively charged

a region of DNA is chosen
DNA is extracted
DNA is chopped into pieces using restriction endonucleases
fragments are transferred to absorbent paper and placed onto gel; heated to separate DNA strands
short sequences of single-stranded DNA are added. They contain radioactive P isotopes; X-ray results, darken film, the separated fragments become visible

ref. to VNTR (sequences) ;
quantity of DNA increased by PCR ;
DNA fragmented by, restriction enzyme(s) / endonuclease(s) ;
loaded (into wells) in agarose gel ;
(at) negative end/ cathode end ;
ref. to buffer/ electrolyte ;
direct current applied ;
phosphate groups of DNA give negative charge ;
(negatively charged) DNA attracted to, anode/ positive electrode ;
short pieces/ smaller mass, move further/move faster ;
(pieces) transferred to, membrane/ nylon/nitrocellulose/ absorbent paper or Southern blotting ;
heated to separate strands ;
probes/ fluorescent dye, added ;
X-ray film/ UV light/ lasers ;
pattern of stripes/ ref. banding pattern ;