What voltage to choose | Gel electrophoresis

To separate samples by electrophoresis, an electrical field is applied so that negatively charged nucleic acids migrate toward the positive electrode. Hence, electrical parameters governing electrophoresis can impact sample migration and resolution of its constituent fragments [7,8]. The following equations, derived from Ohm’s Law, may be used to express how voltage (V), current (I), and power (P) can influence electrophoresis results. Voltage = current x resistance, or V = I x R Power = current x voltage, or P = I x V Power can be expressed as P = I2 x R, since V = I x R. The resistance (R) during a gel run is intrinsic to the system. For example, buffer (conductivity and buffering capacity), temperature, gel properties (percentage, height, length, number, cross section), etc., of the system all affect the resistance. In a conductive medium, the resistance decreases when the temperature increases, since higher temperatures allow more current flow. Over the course of a gel run, however, the resistance may vary. Another important contributing factor in electrophoresis is heat. Heat generated is directly proportional to the power consumed by the system and is dependent upon buffer conductivity, applied voltage, and resistance. The higher the conductivity of a buffer (especially when composed of small ions), the more the current flows. Current flow is also enhanced by high voltage and low resistance. The rise in overall current flow increases power and heat generated by the system. #NikolaysGeneticsLessons #gelElectrophoresis #gelElectrophoresisExplained #gelElectrophoresisOfDna #gelElectrophoresisProcedure #gelElectrophoresisLab #gelElectrophoresisAnalysis #agaroseGelElectrophoresis #agaroseGelElectrophoresisProtocol #agaroseGelElectrophoresisOfDna #agaroseGelElectrophoresisExplained #dnaGelElectrophoresis #dnaElectrophoresis #electrophoresisOfDna #sdsPageGelElectrophoresis #polyacrylamideGelElectrophoresis #glycerol #TBE