Amplification of a target sequence by PCR is a routine procedure in many biological labs now. While some intend to have a precise sequence without errors, some use error prone PCR, and many just want to know whether their sequence is there or not – that is when I used Promega’s GoTaq® Green Master Mix.
As implied by its name, it is ready to use mix for a PCR reaction. There is no need to adjust the salt concentrations and enzyme units. Just use half the volume of the final reaction (i.e. it is provided at a 2x concentration), add your template and H2O up to the final volume and the PCR reaction is ready to start. I have successfully used the Green Master Mix in 25, 50 and 100 µl reaction volumes. The solution looks green as it contains two different color dyes: Yellow which migrates faster than the primers and a blue dye which moves along with the 3-5 kb DNA fragments on agarose gels. This feature is of great help as the dyes allow you to monitor the movement of the DNA on the gel. In addition, I did not have to use the loading buffer as the GoTaq® Green Master Mix also contains a compound which increases the density of the solution. Both of these features result in time-savings; this was the major reason for me to use the mix. I could run 96 PCR reactions in one go in order to screen my recombinant clones in a 96 well plate and then directly load them on a gel to screen for amplification.
I have used GoTaq® Green Master Mix for my library screening. I had a small stretch of a known sequence and was trying to get the rest of the gene. While I had made a gene library already, I had to screen my library as fast as possible and so I used this master mix to save time. One can imagine preparing 96 reactions: Putting in the dNTPs, enzyme, buffer, and salt separately; GoTaq® rescued me from so much hassle. I highly recommend it for gene library screening. I have also used this master mix for amplifying directly from bacterial colonies in colony screening too.
There is one thing to take into consideration: This master mix contains a nonrecombinant, modified form of Taq DNA Polymerase, not a high-fidelity polymerase. This makes it cheaper, but small errors may be introduced in the amplified sequence. That is why I do not recommend the amplified product be used for cloning purposes. I also purified the PCR product with routine PCR product purification kits and confirmed my PCR product identity with enzymatic digestion.
The product insert also has a very nice PCR protocol for different reaction volumes so that a new person can easily set up a typical PCR reaction without having to bother with lengthy procedures and calculations. The manual is very clear and easy to follow. I strongly recommend reading the protocol before setting up PCR reactions using GoTaq® Green Master Mix.
In conclusion, Promega’s GoTaq® Green Master Mix is very useful and convenient especially when running a large number of PCRs in a short time. It is great for great for library screening and is cost effective. Promega has also launched other master mixes with components that are easy to adjust according to your own requirements. The general guidelines can also be found on Promega’s website. You can also order a sample of GoTaq® Green Master Mix from Promega without much effort and test it yourself. You will come to know why I recommended it.