Ambergen Technology

The sequencing of nucleic acids is one the most powerful and valuable tools for scientific research. As evidenced by the Human Genome project, there is an ever increasing demand for nucleic acid sequence information.

There are numerous methods available for sequencing of nucleic acids. The first methods were developed almost twenty years ago. For example, the Sanger enzymatic (i.e., dideoxy chain termination) method involves synthesis of a DNA strand from a single-stranded template by a DNA polymerase. The Maxam and Gilbert method involves chemical degradation (i.e. chemical cleavage) of the original DNA.

Today, next generation massively parallel sequencing methods are emerging which can decode on the order of gigabases in a single instrument run. One strategy is based on sequencing by synthesis type approaches. In this case, sequencing primers bound to solid-phase template molecules are extended using a polymerase in conjunction with fluorescently labeled and terminated nucleotides. After reading the incorporated nucleotide by fluorescence, both the terminator and fluorophore are removed prior to the next sequencing cycle. Sequencing by ligation strategies can also rely on removal of the incorporated fluorophore.

Ambergen has developed patented photocleavable fluorescent nucleotide conjugates (Figure 1). These conjugates enable the fast and efficient removal of the fluorescent marker for the next sequencing cycle (Figure 2). The high efficiency photocleavage reaction can be achieved in ~5 minutes under low-intensity near-UV light or substantially faster with higher intensity sources. Photocleavage is ideal for massively parallel sequencing where throughput is of utmost importance. No added chemicals are needed and photocleavage can be done in virtually any buffer (e.g. simultaneously with chemical cleavage of the nucleotide terminator).