Your Friend Works at the Centers for Disease Control and Prevention

Multiple Choice

Your friend works at the Centers for Disease Control and Prevention and has discovered a brand-new virus that has recently been introduced into the human population.She has just developed a new assay that allows her to detect the virus by using PCR products made from the blood of infected patients.The assay uses primers in the PCR assay that hybridize to sequences in the viral genome.
Your friend is distraught because of the result she obtained (see Figure 10-28) when she looked at PCR products made using the blood of three patients suffering from the viral disease, using her own blood, and using a leaf from her petunia plant.
You advise your friend not to panic, as you believe she is missing an important control.Which one of the choices listed below is the best control for clarifying the results of her assay? Explain your answer.
Figure 10-28

A) a PCR assay using blood from a patient who is newly infected but does not yet show symptoms
B) a PCR assay using blood from a dog
C) a PCR assay using blood from an uninfected person
D) repeating the experiments she has already done with a new tube of polymerase