As part of our GLP/GMP Cell Bank Characterization services, Southern blot analysis is used evaluate the number of integration site and the expression construct structural integrity. Both integration site number and structure will be evaluated and may be compared to a reference if available.
DNA will be extracted from the test article, non-transfected host cells, followed by UV quantitation and electrophoresis analysis. After restriction digest with up to 4 enzymes, which cut once within the expression system, DNA samples are separated by electrophoresis and then transferred and UV cross-linked to a positive charged nylon membrane. Probe DNA will be prepared and labeled with either Chemiluminescent or 32P chemistry. After hybridization, the captured fragments will be visualized by exposure of X-Ray film. After producing the autoradiogram, the estimation of integration site number and the size of transgene will be reported.