Zyppy™ Plasmid Miniprep Kit From Zymo Research

While the simplicity of most plasmid miniprep kits on the market today would seem to preclude any substantial improvement in the procedure, Zymo Research has managed to accomplish this with the introduction of their Zyppy™ Plasmid Miniprep Kit. The concentrated (7X) lysis buffer in the Zyppy™ kit allows it to be added directly to the bacterial culture, without the need to pellet the cells first. Although pelleting bacteria by centrifugation is not a huge inconvenience, the elimination of any step is a plus. Also, resuspending the pellet can be quite time consuming, particularly with multiple samples.

In addition to eliminating the initial centrifugation step, Zymo has also integrated a few other helpful changes into the standard miniprep protocol. One such improvement is the inclusion of tinted lysis (blue) and neutralization (yellow) buffers. After adding the neutralization buffer to the lysed cell suspension, you simply mix the tube until the whole solution is yellow, which indicates neutralization. No more wondering if 4 to 6 tube inversions is sufficient to neutralize the reaction. Other beneficial changes concern the overall configuration of the spin column and the size of the collection tube. The spin column matrix has a smaller diameter and is deeper than most others, which permits smaller washing and eluting volumes. The combination of smaller wash volumes with the 2 ml collection tubes means that the collection tube doesn’t have to be emptied as frequently between spins. In addition, the centrifugation of the spin column in an empty collection tube to ensure removal of all wash buffer is eliminated. After transferring the cleared bacterial lysate to the spin column, only 3 spins of 15 sec each are required before eluting. Finally, the spin columns are equipped with a small numbered tab to do away with the need for manually numbering the columns.

I recently tried the Zyppy™ Plasmid Miniprep Kit alongside another popular brand of miniprep kit. The results of triplicate plasmid purifications from 0.6 ml overnight culture are shown in the table below. I used the elution volumes recommended by the respective kits (30 µl for the Zyppy™ prep and 50 µl for Brand Q).

The Zyppy™ kit averaged about 1 µg more plasmid DNA than the other kit. The 260/280 ratio was slightly lower for the Zyppy™ kit but still indicative of very pure DNA. I ran 250 ng of plasmid isolated using each kit on a 1% TAE gel. A picture of the pertinent gel regions is shown to the left. As can be seen in the photo, both plasmids look very good with the major staining band being the faster migrating supercoiled form of the plasmid.

In short, the Zyppy™ Plasmid Miniprep Kit performed exceptionally well, was simple to use, and was very fast. Depending on the package size (50, 100, or 400 preps), you’ll pay between $0.80 and $1.00 per prep. A free trial offer is available from the Zymo Research website.