Practice question

Band morphology reflects gel quality, electrical parameters, and sample integrity. Under optimal conditions, uniform pore distribution, proper buffer ionic strength, controlled voltage limiting Joule heating, and adequate polymerization produce minimal diffusion. DNA molecules of identical length migrate as tight zone, concentrating fluorescence in narrow region. This yields sharp, well-defined bands with high contrast. Smear indicates overloading, degradation, or excessive heating; faint suggests insufficient DNA; diffuse indicates poor polymerization or high electroendosmosis. Sharp appearance therefore correlates with high quality and correct conditions.