You're trying to PCR amplify a gene, but your gel shows that there are two bands instead of only one like you expected. You know for certain that there no homologous genes in the genome from which you're amplifying, so you assume that the issue must be coming from your primers or PCR conditions. Briefly describe 2 different strategies for solving the problem and how they work.

5. You have sequenced a human protein gene from genomic DNA. You would like to use E. coli as mechanism to express this protein. Identify and briefly describe two modifications you might have to make to make to your sequence in order to have successful expression.

6. Restriction fragment length polymorphism (RFLP) analysis is commonly used for tracing the relatedness of pathogenic microorganisms in food-related disease outbreaks. Often, this technology can allow epidemiologists to identify the source of the contamination and thus what foods may need to be recalled. Describe the molecular principles underlying RFLP and how they enable this type of epidemiological analysis.