Can I use a QIAfilter Cartridge for purifying large plasmids?
Data from QIAGEN laboratories show that cosmids of up to 45 kb can be purified using the QIAfilter procedure without any detectable DNA shearing (see figure below).
Note: Many large plasmids are present in very low copy number in cells. For very low-copy-number constructs, refer to the special protocol 'Very Low-Copy Plasmid/Cosmid Purification using QIAGEN-tip 100 or QIAGEN-tip 500 in the QIAGEN Plasmid Purification Handbook. For purification of constructs larger than 50 kb (up to 250 kb) we recommend using the QIAGEN Large-Construct Kit.
Note: Many large plasmids are present in very low copy number in cells. For very low-copy-number constructs, refer to the special protocol 'Very Low-Copy Plasmid/Cosmid Purification using QIAGEN-tip 100 or QIAGEN-tip 500 in the QIAGEN Plasmid Purification Handbook. For purification of constructs larger than 50 kb (up to 250 kb) we recommend using the QIAGEN Large-Construct Kit.