:Patientswith a particular form of hemophilia (a deficiency in bloodclotting) have a loss of an EcoRI restriction site within the genefor a coagulation factor protein. In one family with an affectedson, PCR analysis was carried out on blood samples from a malefetus and from several family members to determine whether thefetus carried the mutation. Following PCR amplification of theappropriate 150 bp (base-pair) DNA fragment, the fragments wereincubated with EcoRI and the resulting cleavage fragments separatedby electrophoresis on an agarose gel and stained with ethidiumbromide.
Will the fetus have hemophilia? Explain. Given that the EcoRI restriction digest is "complete" (i.e. all DNA that can be cut is cut), explain why there are 3 bands in the Mother's lane. This analysis can also be done by using Southern blotting to detect single-copy sequences in genomic DNA. Why is the PCR analysis preferrable (i.e. what are the benefits of PCR vs. Southern blotting)?
