In Vitro: Guidelines (Following is our recommended protocol. This protocol only provides a guideline, and should be modified according to your specific needs). The preparation of agarose gel: 1. Agarose gels are commonly used in concentrations of 0.5% to 2.5% depending on the size of bands needed to be separated. 2. Mix the agarose powder with 1X TAE/TBE. 3. Microwave for 1-3 min until the agarose is completely dissolved (Caution: not overboil). 4. Make the solution cool down before solidification. 5. Add ethidium bromide (EtBr) to a final concentration of approximately 0.2-0.5 μg/mL (Stocks are generally 10 mg/ml, and require 5 µL stock/100 mL gel). 6. Ethidium bromide binds to the DNA and you could visualize the DNA under ultraviolet (UV) light. CAUTION: EtBr is a known mutagen. Please pay attention to strengthening protection.