Preparation of samples
Remove aliquots from the cleared lysate (sample 1), flow-through (sample 2), combined Buffer QC wash fractions (sample 3), and Buffer QF/QN eluate (sample 4), as indicated in each protocol and in table below. Precipitate the nucleic acids with 1 volume of isopropanol, rinse the pellets with 70% ethanol, drain well, and resuspend in 10 µl TE buffer, pH 8.0.
Sample volumes required for agarose gel analysis
|Sample||Protocol step||Midi||Maxi||Mega||Giga||(Very low-copy
|1||240 µl||120 µl||120 µl||75 µl||600 µl||750 µl|
|2||240 µl||120 µl||120 µl||75 µl||50 µl||24 µl|
|3||400 µl||240 µl||160 µl||120 µl||200 µl||120 µl|
|4||100 µl||60 µl||22 µl||20 µl||50 µl||30 µl|
|(% of prep represented
by each sample volume)
Agarose gel analysis
Run 2 µl of each sample on a 1% agarose gel* for analysis of the fractions at each stage of the plasmid purification procedure. This figure shows an analytical gel of the different fractions, together with examples of problems that can arise at each step. If you find that you have a problem with a particular step of the protocol, turn to the hints in the relevant section of the troubleshooting guide in the handbooks. If the problem remains unresolved, or if you have any further questions, please call QIAGEN Technical Service.