(1) Sample tissue was not lysed completely: Add additional Proteinase K and extend the incubation time in the Lysis step. (2) Column was clogged at the DNA Binding Step: Following the Lysis Step, remove the insoluble debris by centrifugation. Prior to loading the column, break up the precipitate in ethanol-added lysate. (3) Incorrect DNA Elution Step. Ensure that Elution Buffer was added and absorbed to the center of the GD Column matrix. (4) Incomplete DNA Elution. Elute twice to increase the DNA recovery.
Why is the DNA recovery lower than expected? "