A report from Chittaranjan et al. (2009) Steroid Hormone Control of Cell Death and Cell Survival: Molecular Insights Using RNAi. Free online access from PLoS Genetics. (Figure show is from this report.)
Like the report from Rogers et al. that I blogged about in a previous post (Little Screens, Big Results), these authors focused their screen on a set of candidate genes. In this case, a set of 460 candidates. To do this, the authors generated dsRNAs for each candidate and followed up with a second dsRNA for screen hits.
Chitteranjan et al. performed what is essentially two screens. One focused on identification of pro-death and pro-surivival factors. And the other on "death related effects" dependent upon or independent of ecdysone treatment.
Protocol notes: Their screen was done on ecdysone-treated l(2)mbn cells. Death and survival monitored with what I think of as an old-school (but reliable) approach, a trypan blue exclusion assay. And they took a closer look at cell death with DAPI staining and TUNEL analysis.
Some thoughts: Reading another report like this focused on a defined set of candidate genes has me excited for something the DRSC has just begun to offer: synthesis of custom sets of dsRNAs in 96-well format (based on existing amplicons).
This made sense as (1) we're expert at doing IVTs at high-throughput, including quality analysis and troubleshooting, and have ready access to our collections of PCR amplicons used as templates for the dsRNA. And (2) the increasing interest in the community to screen a custom-curated sets of genes.
We just successfully completed a pilot project and given the right lead-time, can now accommodate more requests.
Please contact me if you're interested to learn more about the service.