Instruction Manual

11
Section 7
Troubleshooting Guide
Problem Possible Cause Possible Solution
Low plasmid yields Low copy number Use high copy number
plasmid constructs
Poor plasmid Inoculate large-scale
propagation in culture cultures with overnight
cultures generated from
fresh colonies grown on
a selective medium
Determine optimum
growth and plasmid
propagation times for
culture depending upon
host, broth, etc.
Check age and
concentration of
antibiotic
Excessive amount of Determine OD
600
of
bacteria processed culture and reduce
OD•ml of bacteria
processed to ensure
efficient lysis
Incomplete resuspension Ensure that the bacterial
of bacteria pellet pellet is completely
resuspended prior to
addition of lysis solution
Excessive drying of See protocol. Do not
column membranes exceed 1 min
prior to elution centrifugation.
Insufficient ethanol Check that correct
added to wash solution amount was added
concentrate