It is pretty clear that upon investigating the safety data sheet, which shows three trade secret components in the EU version, two of these are DMSO and glycerol, based on the unique toxicity and ecotoxicity measurement values shown across the EU, Canada/Mexico, and US safety data sheets.

Using the same "investigative methodology," Q5 reaction buffer appears to have glycerol, which reduces DNA secondary structure, and tetramethylammonium, which increases primer stringency. Phusion buffer doesn't appear to have these.

Dear Harini,

I hope you find the following link useful:

https://international.neb.com/products/m0491-q5-high-fidelity-dna-polymerase#Product%20Information

It has much information about the Q5 DNA polymerase, as well as several FAQS and Tech Tips for a correct usage.

Best regards,

Tomás

Hello, In contrast to chemically modified or antibody-based hot start polymerases, Q5 utilizes a unique synthetic aptamer. This molecule binds to the polymerase through non-covalent interactions, blocking activity during the reaction setup. The polymerase is activated during normal cycling conditions, allowing reactions to be set up at room temperature. Q5 does not require a separate high temperature activation step, shortening reaction times and increasing ease-of-use. Q5 Polymerase is an ideal choice for high specificity amplification and provides robust amplification of a wide variety of amplicons, regardless of GC content.

Hi,

It is used along with GC buffer when the GC content of the primer is high.

thanks Tomás Monteiro Fernandes Karen A. Darbinyan Parismita Kalita

It is used in PCR for difficult amplicons, such as GC-rich templates, the addition of the Q5 GC Enhancer improves the reaction performance

I speculate the GC enhancer contains DMSO, which interferes with secondary structure formation in GC-rich regions. Unfortunately, Qiagen doesn't release this information to the public, probably because they spent research dollars in developing a proprietary formula.