QIAGEN Plasmid Plus Maxi Sample Kit (5) QIAGEN Plasmid Plus Kits enable ultrafast, large-scale plasmid purification of pure plasmid DNA. The use of a vacuum manifold allows purification of up to 12 (Mega and Giga) or up to 24 (Midi and Maxi) samples in parallel with low hands-on needs. Low elution volumes yield highly concentrated plasmid DNA for direct use without ethanol precipitation. QIAGEN Plasmid Plus Kits also feature a novel wash buffer for endotoxin reduction.