Location

Chemical Screening

The HTB unit maintains many collections of chemical libraries and houses  instruments needed to process large amounts of samples in high throughput fashion. Our platforms include plate-based screening of cells and biochemical screens. We support both plate reader assays and high content microscopy.

How to get started?

All projects are customized to a researchers needs. A typical workflow for chemical screening is shown here

If you are interested in any of our services for application of your project, please complete the online project contact form and we will contact you.

Assay Development and HTS optimization

Assay development starts by identifying the target and its activity. The next step is determining whether the objective is to inhibit or activate the target. A great starting point for assay development is a bench scale assay for the target used by the principal investigator, who initiates the small molecule screen by contacting the FIMM HTB unit. A small molecule chemical screen can be cell-based or based on a biochemical assay. The assay developers at FIMM HTB unit set up the assay and optimize it for high throughput screening.

With positive and negative controls, we confirm that assay repeatedly gives a Z'-factor >0.5.  The positive control can be either a small molecule inhibitor that inhibits the reaction in question or a reaction without the enzyme of interest. Next, we test DMSO tolerance since our compound libraries are dissolved in DMSO. For biochemical assays, a final DMSO concentration between 1 and 5% is often convenient - it allows for flexibility with compound addition and supports solubility of compound. Whole cell assays normally tolerate no more than 0.5-1% DMSO.

Besides the primary assay, we also preferentially develop one or more counter screens (similar assay where an inhibitor should not hit) and an orthogonal assay (assay designed to test for inhibition of the same process but with a different readout to sort out compounds interfering with the readout).

After primary assay development, the assay is miniaturized using HTS equipment to 384- or 1536-well format and re-tuned for high-density format.

Finally, two full Z'-plates with negative and positive controls are prepared and measured to test the reproducibility and precision of the assay and to detect any positional plate effects and systematic liquid handling errors.

 

Last updated: 28.10.2016 - 15:21