Saccharomyces Genome 4X larger than E . Somatic cell gene therapy - norma genes replace defective genes in humans. Centrifugation at different speeds. Isopycnic gradient centrifugation. Bottom of gradient denser than top.
Particles come to rest in the gradient according to their densities.
Rate-zonal gradient centrifugation. Bottom of gradient less dense than virus. Virus are sedimented. Precipitation of viruses. Ammonium sulfate or polyethylene glycol precipitates viruses.