To clear up a possible confusion around microarrays, SNP sequencing, and GWAS—microarrays are also used to directly measure gene expression (as opposed to trait expression) by hybridizing mRNA extracted from a tissue sample and hybridizing that against a library of known RNA sequences for different genes. This uses the same technology as microarray-based GWAS, but for different purpose (gene expression vs. genomic variation), and with different material (mRNA vs amplified genomic DNA) and analysis math.
Also, there’s increasingly less reason to use microarrays for anything. It’s cheap enough to just sequence a whole genome now that I’m pretty sure newer studies just use whole genome sequencing. For scale, the lab I worked in during undergrad (midsized lab at a medium sized liberal arts college, running on a few 100k $/yr) was transitioning from microarray gene expression data to whole-transcriptome sequencing back in 2014. There’s a lot of historical microarray data out there that I’m sure researchers will still be reanalyzing for years, but high throughput sequencing is the present and future of genomics.
Do you have any sense as to how much it costs to sequence a whole human genome right now? I estimated about $300, but that was based on essentially one vendor.
Hey, sorry for the long time replying—last I checked, it was a few hundred $s to sequence exome-only (that is, only DNA that actually gets translated into protein) and about $1-1.5k for whole genome—but that was a couple of years ago, and I’m not sure how much cheaper it is now.
To clear up a possible confusion around microarrays, SNP sequencing, and GWAS—microarrays are also used to directly measure gene expression (as opposed to trait expression) by hybridizing mRNA extracted from a tissue sample and hybridizing that against a library of known RNA sequences for different genes. This uses the same technology as microarray-based GWAS, but for different purpose (gene expression vs. genomic variation), and with different material (mRNA vs amplified genomic DNA) and analysis math.
Also, there’s increasingly less reason to use microarrays for anything. It’s cheap enough to just sequence a whole genome now that I’m pretty sure newer studies just use whole genome sequencing. For scale, the lab I worked in during undergrad (midsized lab at a medium sized liberal arts college, running on a few 100k $/yr) was transitioning from microarray gene expression data to whole-transcriptome sequencing back in 2014. There’s a lot of historical microarray data out there that I’m sure researchers will still be reanalyzing for years, but high throughput sequencing is the present and future of genomics.
Thanks for the detail about microarrays.
Do you have any sense as to how much it costs to sequence a whole human genome right now? I estimated about $300, but that was based on essentially one vendor.
Hey, sorry for the long time replying—last I checked, it was a few hundred $s to sequence exome-only (that is, only DNA that actually gets translated into protein) and about $1-1.5k for whole genome—but that was a couple of years ago, and I’m not sure how much cheaper it is now.