High-throughput Screening
Overview
High-throughput screening (HTS) is a method for scientific experimentation especially used in drug discovery and relevant fields of biology. It involves the use of automated equipment to rapidly test the biological or biochemical activity of a large number of molecules, usually drugs or genetic materials. This method is a significant part of the early stages of drug discovery process where it is used to identify active compounds, antibodies, or genes which modulate a particular biomolecular pathway.
History
The concept of high-throughput screening was first introduced in the late 20th century. The need for a more efficient way to screen potential drug candidates led to the development of this technique. The first HTS system was developed by the NIH in the 1990s. Since then, the technology has evolved and improved, allowing for the screening of larger libraries of compounds with increasing speed and accuracy.
Methodology
High-throughput screening is performed using a robust and reliable assay, which is then miniaturized into a high-density format, such as 96, 384, or 1536 well plates. The key to HTS methodologies is the ability to perform these assays in a parallel, rather than sequential manner. This allows for the screening of large libraries of compounds, often exceeding hundreds of thousands of tests in a single day.
Assay Development
The first step in HTS is the development of a suitable assay that is both reliable and can be miniaturized. This assay must be able to test the desired biological or biochemical activity. There are many types of assays that can be used, including cell-based assays, biochemical assays, and genetic assays. The choice of assay depends on the nature of the biological target and the type of activity that needs to be tested.
Library Screening
Once the assay has been developed, the next step is the screening of a library of compounds. These libraries can be made up of a variety of different types of molecules, including small organic molecules, peptides, or RNAi. The library is added to the assay in a high-density format, and the assay is then run. The results of the assay are then analyzed to identify any hits, or compounds that show the desired activity.
Hit Validation and Optimization
After the initial screening, any hits are then validated to confirm their activity. This is often done by retesting the hits in the same assay, as well as in secondary assays. Once the hits have been validated, they can then be optimized. This often involves chemical modifications to improve the potency, selectivity, and pharmacokinetic properties of the hit compounds.
Applications
High-throughput screening has a wide range of applications in the field of drug discovery and development. It is used to identify potential drug candidates in the early stages of drug discovery. It is also used in the field of genomics to identify genes that are involved in a particular biological pathway. In addition, HTS can be used in the field of proteomics to identify proteins that interact with a particular drug or other compound.
Advantages and Limitations
High-throughput screening offers several advantages over traditional methods of drug discovery. It allows for the rapid screening of large libraries of compounds, which can greatly speed up the drug discovery process. It also allows for the identification of novel targets and the discovery of new drug classes.
However, HTS also has some limitations. The high cost of screening large libraries of compounds can be prohibitive for some organizations. In addition, the high rate of false positives and negatives can be a challenge. Despite these limitations, HTS remains a powerful tool in the field of drug discovery and development.