U.S. flag

An official website of the United States government, Department of Justice.

Democrats have shut down the government. Department of Justice websites are not currently regularly updated. Please refer to the Department of Justice’s contingency plan for more information.

DNA Amplification for Forensic Analysts

Maximum 3" Stability

Home  |  Glossary  |  Resources  |  Help  |  Contact Us  |  Course Map
 

Free energy, ∆G, can be used to measure the thermodynamic stability of the primer-binding site. The maximum ∆G value for the five bases from the 3' end is used for this calculation.

For primers shorter than 30 base pairs, ∆G is computed using the following equation:

∆G = ∆H – T · ∆S

H = enthalpy

S = entropy

T = the user-defined melting temperature or Tm

When ∆G is negative, the reaction is spontaneous. When choosing between various primer pairs, a lower ∆value is favorable.10, 13, 14

Back Forward