Use the Following to Answer Questions

Multiple Choice

Use the following to answer questions
A student carries out PCR using the following steps:
Step 1: 94°C for 1 minute
Step 2: 60°C for 30 seconds
Step 3: 72°C for 30 seconds
-After electrophoresing his PCR reaction, the student sees the desired PCR product on the gel as well as several smaller bands. What error(s) might he have made? (Select all that apply.)

A) He carried out step 2 at too low a temperature
B) He carried out step 2 at too high a temperature.
C) He designed primers with repetitive sequences.
D) He contaminated the template DNA sample.
E) He carried out step 3 for too short a time.