The GenomiPhi DNA Amplification Kit by GE Healthcare (formerly Amersham Bioscience) is a whole genome amplification kit that enables users to perform unlimited DNA tests from small or limited samples.
The GenomiPhi kit utilizes bacteriophage Phi29 DNA polymerase to exponentially amplify single- or double-stranded linear DNA templates via a strand displacement reaction and therefore thermal cycling is not required. The genomic DNA vtemplate is combined with a sample buffer containing random hexamer primers. The mixture is heat denatured and cooled to allow random priming of the hexamers. Then, the remaining reaction components— including Phi29 DNA polymerase, deoxynucleotide triphosphates, and buffer components optimized for linear DNA synthesis—are added. This reaction mixture is incubated overnight at 30ºC, during which time the available nucleotides are consumed and converted into high molecular weight fragment copies of the template DNA. The DNA replication is extremely accurate because of the proofreading activity of Phi29 DNA polymerase. Once genome amplification is completed various genotyping assays can be undertaken from a large base of synthetic DNA copies. My STR analyses of DNA amplified using the GenomiPhi kit has been successful.
I have used the GenomiPhi DNA Amplification Kit with carnivore blood and tissue samples that were stored in a Longmire lysis buffer solution at room temperature for periods of up to 8 years. In several cases extracted DNA was extremely small (i.e., originating from 0.001 ml blood/10 ml lysis solution), and amplification was successful. Furthermore, although the Phi29 DNA polymerase enzyme is supposedly sensitive to degradation at higher temperatures (GE Healthcare (formerly Amersham Biosciences) recommends storage at – 70ºC), I found the GenomiPhi DNA Amplification kit to work well after >3 days at room temperature.
In my lab this kit it is particularly useful for the amplification of international endangered wildlife species DNA that cannot be exported to the USA due to CITES and other restrictions. Because I work with small samples under a limited time frame it is important to have a robust protocol for amplifying the entire genome. A further advantage of this product is the small size of the kit and minimum equipment needed for amplification. The kit is easily transportable when packed with ice packs, and analysis can be done from a hotel room if necessary. The instruction manual is laid out in cookbook fashion and is very easy to comprehend. The manual covers all aspects of the amplification protocol, including excellent figures and notes, and has a troubleshooting guide. The price of about $500 for 100 reactions is reasonable when one considers the versatility and output of the kit.
My only complaint is the claim that it has a limited shelf-life at room temperature, when in fact I found it to be stable at room temp for over 3 days. An increase in shelf-life at higher temperature would greatly increase the attractiveness of this kit, particularly as pertains to research in remote locations where access to – 70ºC freezers may be limited.
Based on my positive experience both abroad under difficult laboratory conditions, and at home in my modern lab, I wholeheartedly recommend the GenomiPhi DNA Amplification Kit for anyone who requires rapid whole genomic amplification from meager to modest samples of extracted DNA.
Lon I. Grassman, Jr., Ph.D.
Feline Research Center
Casesar Kleberg Wildlife Research Institute
Texas A&M Unversity – Kingsville