Illumina Genome Analyzer II

Illumina GAII was a pioneering next-generation sequencing (NGS) system that significantly advanced genomic research in the early 2010s. Launched in 2009, this instrument offered high-throughput and accurate sequencing capabilities, making it a valuable tool for various applications in biotechnology and related fields.

Key features of the GAII included:

• Enhanced optics and detection: Incorporated refined optics, lasers, and a more sensitive CCD camera, improving signal-to-noise ratios and accuracy.

• Increased cluster density: Achieved higher cluster densities on the flow cell surface, enabling a significantly higher sequencing output per run.

• Paired-end sequencing capability: Introduced paired-end sequencing, generating reads from both ends of a DNA fragment, enhancing genome assembly and structural variant detection.

• Sequencing by Synthesis (SBS): Employed SBS chemistry, where fluorescently labeled nucleotides are sequentially incorporated, with images captured after each flow cycle to determine the added base.

• Bridge amplification: Utilized proprietary bridge amplification to create dense clusters of identical DNA templates on the flow cell, amplifying signals for detectable output.

• High data quality: Achieved base call accuracy exceeding 99% for more than 85% of bases, with the ability to produce up to 150 gigabases of sequencing data per run.

The GAII was widely adopted in genomics, molecular biology, and biotechnology research, facilitating applications such as:

• Whole genome sequencing: For both human and model organism research.

• Resequencing: Targeting and sequencing specific genomic regions of interest.

• Transcriptome sequencing (RNA-Seq): Analyzing gene expression patterns.

Commonly utilized in university laboratories, biomedical research centres, and biotechnology companies, the GAII played a crucial role in advancing genomic studies. Although discontinued in 2014, its legacy continues to influence current sequencing technologies.