High-Throughput Screening - Facts

High-throughput Screening

High-throughput screening (HTS) is the process of rapid and simultaneous testing thousands of experimental conditions or treatments using lab automation equipment. Screens can be (bio-) chemical or biological and can be used for many research topics, including for example the identification of enzyme binding partners, lead identification, disease target identification or drug repurposing approaches.

Assay Miniaturization

Screening assays are done in multi-well plates, typically 96- or 384-well plates, and in the case of biochemical assays also in 1536-well format. Miniaturization of the working volume in 384- and 1536- well plates allow for higher cost-efficiency per test condition, but past 384-well plates may not always be compatible with the assay or available automation equipment.
The process of miniaturization from 48- or 96-well plates to e.g. 384-well plates is not straightforward and requires careful experimental planning and testing. Different reaction- or cell culture medium volumes may affect the assay reaction speed or cell growth rate. Additionally, many plate types are commercially available and the selection of the correct plate type is of the utmost importance.

Assay Automation

Automation of screening experiments has facilitated miniaturization and thereby enormously improved the throughput of screens over the last decades. In addition, lab automation also improves assay robustness and reproducibility by increasing the liquid transfer accuracy. Traditionally, one would track time-sensitive experiments with a stopwatch for each plate and work in a sequential way. Scheduling of automated screening assays ensures that all plates undergo the same treatment at the correct time, and allows experiments to run single assay plates in parallel.

Assay Quality

Control conditions in each plate have to be included in a way that the measurements can be standardized and hits can be identified. Therefore, the difference between included positive- and negative controls (active and inactive controls, respectively) has to be sufficiently large.
Important: Appropriate care must therefore be taken when selecting control conditions as these are the backbone of each screening campaign.