Biology 2581B Lecture Notes - Lecture 4: Sickle-Cell Disease, Gel Electrophoresis, Hybridization Probe
15 Mar 2015
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Document Summary
Sickle cell anemia: single base pair substitution resulting in single amino acid chain in -globin, glutamic acid to valine change, promotes aggregation of hemoglobin under low oxygen conditions which distorts shape. Huntington"s disease: cag repeats, near the 5" end of coding region, different alleles have different numbers of repeating units. 20 repeats = normal: small proportion of snps by chance eliminate or create a restriction site recognized by restriction enzymes, most common type of genetic variation, spontaneous or induced, base pair substitutions, single strand. Southern blot: dna treated with restriction enzyme, hybridized with dna probe obtained between the region of polymorphic restriction site and adjacent non polymorphic restriction site, different snp alleles change the size of hybridizing restriction fragment. Pcr: amplification of several hundred base- pair region encompassing snp, exposure of pcr products to appropriate restriction enzymes, evaluation of samples by gel electrophoresis and staining, reading of size of dna fragment. Hybridization: change in stringencies of probe binding, short probe.
