DNA fingerprinting Flashcards
the two methods of fingerprinting are?
restriction fragment length polymorphism (RFLP) and short tandem repeat (STR)
the purpose of DNA fingerprinting is?
to detect sequence variations that make each individual’s DNA unqiue
how are polymorphisms used in DNA fingerprinting?
since people have 99% identical DNA, polymorphisms are stretches of repetitive and highly variable DNA which is exploited
the first step of restriction fragment length polymorphism analysis is?
restriction endonucleases are used to cut 10-100 base pair stretches of polymorphic DNA into small fragments (varying in size)
the resulting DNA fragments are referred to as RFLPs
the second step of RFLP analysis?
the RFLPs are separated via gel electrophoresis and transferred to a membrane
the third step of RFLP analysis?
southern blotting is performed to analyze the sample
polymorphic DNA will yield unique band distribution for each person and mutations can be detected
what is an example of real life of RFLP analysis?
sickle cell disease, which is caused by a single base substitution in the beta chain of hemoglobin
the substituted valine in the sixth position (typically glutamic acid) will introduce novel restriction site within the gene
the first step of short tandem repeat analysis (STR)?
uses PCR to amplify 5-10 base pair stretches of highly polymorphic and repetitive DNA located within noncoding regions of the genome
*to profile an individual, a sample of DNA is obtained and the polymorphic DNA is amplified with PCR
the second step of STR analysis is?
the amplified STRs are separated via electrophoresis and analyzed with southern blotting
