Difference between denaturation and renaturation of DNA

Definition:

• Denaturation: The process of formation of single stranded DNA from double stranded helical DNA upon heating.

• Renaturation: The process of formation of double stranded DNA (reannealing) from single stranded DNA upon cooling.

Denaturation

1. The process of formation of single stranded DNA from double stranded helical DNA

2. It is effected by heating

3. It involves breakage of hydrogen bonds between complementary base pairs

4. The increase in absorbance (A260) upon denaturation is called as hyper chromic effect

5. The rate of increase in absorbance is directly proportional to the rate of denaturation

6. Upon denaturation, viscosity decreases

7. Detected by measuring UV absorbance at 260nm

Renaturation

1. The process of formation of double stranded DNA from single stranded denatured complementary DNA strands

2. It is effected by cooling

3. It involves reannealing or formation of hydrogen bonds between complementary base pairs.

4. There is a decrease in absorbance (A260) upon renaturation

5. The rate of renaturtion is directly proportional to the concentration of complementary sequences.

6. Upon renaturation, viscosity increases

7. Detected by measuring UV absorbance at 260nm

Applications of DNA denaturation and renaturation kinetics

• Understanding genome size and complexity
• Understanding genetic relatedness
• Understanding relative proportion of single copy and repetitive sequences