I have used plasmid mini-prep kits from many different companies. But recently I began using the 5 PRIME FastPlasmid Mini kit and I feel it is the best among the various kits that I have used.
This kit is similar to other mini-prep kits available. The biggest difference that I’ve found is that it is extremely easy to use. The protocol is straight-forward; after spinning down the bacteria, the pellet is re-suspended in 400 µl of lysis buffer, vortexed (at least 30 sec) to suspend the bacteria, incubated for 3 min to allow lysis, is then transferred to a spin column. The column is spun for 0.5-1 min at maximum speed and 400 µl of wash solution is added and the column is spun again (to remove traces of wash buffer). The column is then transferred to a new collection tube, elution buffer is added and there is one last 1 minute spin. Now the plasmid is ready to use.
From this overview, you can see how simple and fast the procedure is. Instead of having to use buffers 1, 2 and 3 to lyse the bacteria, there is only one lysis buffer to resuspend and lyse the cells at the same time. After lysis, there is no need to spin the lysate, it is directly transferred to the column, which saves time. So the total hands on time for this kit is much shorter than other kits that I have used. In my hands, using this kit I can isolate 10 mini-preps in less than 20 min (including labeling the tube and columns). This kit is not only fast, but the quality and the yield are also comparable to other kits. The price is good too – each prep costs around $1.
The only extra step in this protocol is the preparation of the lysis buffer; the lysozyme in this kit needs to be dissolved in RNase A solution first, then transferred to the Lysis buffer. This is one step more than other kits, but this is done only once for the whole kit. The real disadvantage of this kit is that the lysis buffer should be ice-cold. If you keep the buffer at 4oC, you have to leave it on ice for at least 10 min before you start mini-prep. But you could use this period of time to label tubes and spin down the bacteria. So normally, there is no wasted time.
So far I have only used this kit with two cell types: DH5á and TOPO 10 cells (from Invitrogen TOPO Cloning kit). It is possible that results may vary with other cell types so it might be worthwhile to contact 5 PRIME customer service for more information.
Rui Wang
Postdoctoral Fellow
Department of Cancer Biology
University of Massachusetts, Medical School
At the time of this review the FastPlasmid Mini Kit was commercialized by Eppendorf. Today it is available from 5 PRIME. This review was edited to reflect this fact.