Advances in Genetic Research

Microarrays

Microarrays are tiny chips with thousands of DNA spots that can analyze many genes at once. Scientists put labelled genetic material on the chip and the material binds to specific spots. The chip is then scanned to see which genes are active or if there are genetic variations. Microarrays help researchers understand how genes work and find important differences between individuals. They have been used in cancer research, personalized medicine and agriculture. Microarrays provide massive amounts of information quickly and have improved understanding of biology. The Centre for Applied Genomics (TCAG) at SickKids has introduced most new microarray products in Canada and is the primary source of this data for scientists in our country.  

Sequencing flow cells

Photo depicts Illumina Genome Analyzer II flow cells (circa 2007).

The flow cell is an important part of a modern DNA sequencing system. It helps process many DNA fragments at once, allowing for fast and accurate sequencing. The flow cell comes in different versions that vary in their capacity and reading capabilities. It uses advanced technology to create tiny wells that hold individual DNA fragments. The flow cell is used for a wide range of applications, from studying genomes to analyzing gene expression. SickKids was the first laboratory in Canada to adopt Illumina’s flow cell technology which was foundational for the massive autism genome sequencing project between Google, Autism Speaks and SickKids, as well as many cancer genome sequencing projects. 

Patterned Flow Cell Technology

Patterned flow cell technology is a feature in more recent sequencing systems that arranges tiny wells in a specific pattern. This helps efficiently capture DNA fragments and improves sequencing accuracy by preventing errors. It is especially useful for large-scale genome sequencing projects, allowing high-throughput and reliable data generation. This technology was the driving force behind decoding the genomes of 10,000 people severely affected by COVID-19 (2020–2023). This collection of data formed the first whole genome sequence resource of a Canadian population. 

PacBio SMRT-cells

SMRT-cells are small chips used in the PacBio systems for DNA sequencing. They have tiny wells where individual DNA molecules are captured. The DNA is read in real-time and is copied using fluorescently labeled building blocks. This process creates long accurate reads of the DNA sequence. The number of wells in the SMRT-cell determines the amount of DNA that can be sequenced at once. These cells are useful for studying genomes, identifying genetic changes and understanding how genes work. This technology is typically used to generate de novo genome assemblies of non-human species. With much fanfare in 2017, celebrating Canada’s 150th birthday, SickKids used this technology to sequence the genome of Castor canadensis, our country’s national animal — the beaver. Our research participant was “Ward the Beaver,” a resident of the Toronto Zoo until his death in 2022.