MoBio Plasmid Purification and Gel Extraction Kits - Problems with MoBio Kits (Feb/13/2008 )

I love the MoBio Soil DNA extraction kit and have used it for many years. I have always done my Plasmid purifications and gel extractions with the Qiagen kits and thought I would try the MoBio versions of these kits since they are much simpler and faster. The results have been more than disappointing with very low yeilds for both the MoBio Gel Extraction and 6min Plasmid Purification kits.

Has anyone had good luck with these MoBio kits? Should I just go back to the Qiagen versions which take a lot more time to do but which give much better yields for me? I am curious what kits other people have used for Gel Ex. Plasmid pur. and also PCR pur.

What kits work best for you?

I would love to find a kit that is faster than the Qiagen kits and which also give high yeilds.

Well, I've been using the Mobio kit for my maxipreps and i like it. Half the price of the Qiagen kit and quicker too. It works fine in my hands, yields are good, but i have little experience with it and no experience with the other Mobio kits so don't have any technical advice for you I'm afraid. If it's 6 minutes though, geez, you can't expect much from it can you? It's built for speed not performance. Also, Qiagen are the world leader for a reason. My advice would be just stick with what works. Even if it takes longer, isn't it worth it to get the desired result? Science is hard enough as it is.

Good luck,
Rob

Thanks Rob for your feedback.

I decided to do a side-by-side comparison of the MoBio and Qiagen kits for plasmid prep and gel purification. I carefully followed the manufacturer’s directions for each kit. So here it is:

UltraClean 6 Minute Mini Plasmid Prep Kit (MoBio) versus QIAprep Spin Miniprep Kit (Qiagen)

Methods:
1) A ten ml culture of E. coli TOP10 cells with a 4000bp plasmid was grown up overnight in Magnificent Broth (MacConnell Research) a medium designed for high plasmid yields. 100ug/ml ampicillin was provided to retain plasmid.
The OD600 of the culture was 5
2) 4ml of this thoroughly mixed culture was pelleted for use in each kit.
3) Manufacturer’s directions were followed for each kit and the DNA was eluted into 50ul of each kit’s elution buffer.

Results:
The MoBio Kit yielded 22ng/ul for a total of 1.10ug DNA
The Qiagen kit yielded 295ng/ul for a total of 14.75ug DNA

800ng of the resulting purified plasmid DNA was run out on a gel with a Mass Ruler, High Range (Fermentas). The expected plasmid band at 4000bp was 80ng for the MoBio Kit and 400ng for the Qiagen Kit, indicating that the Qiagen Kit resulted in less contaminating chromosomal DNA.

The Qiagen Kit resulted in an order of magnitude higher yield of cleaner plasmid DNA than the MioBio Kit.


QIAquick Gel Extraction Kit (Qiagen) versus UltraClean GelSpin DNA Purification Kit (MoBio)

Methods:
1) Identical 3ug bands of 4000bp plasmid DNA were cut out of a 1% agarose gel, 0.3g weight
2)Gel slices processed in each kit according to manufacturers directions
-For Qiagen all extra and recommended steps were preformed.
-For MoBio since the gel slice was 0.3g it was melted in a separated tube and all solution was loaded onto the spinfilter 2X’s as recommended.
4) DNA was eluted into 50ul of each respective Kit’s elution buffer.

Results:
The Qiagen Kit yielded 56ng/ul for a total of 2800ng and a 93% yield
The MoBio Kit yielded 8ng/ul for a total of 400ng and a 13% yield

The Qiagen Kits are clearly giving higher yields.