As more complex diseases enter the development pipeline and “low hanging fruits” become available for patent infringement, scientists require better tools and analytical approaches to effectively address their queries, including cell-based assays that provide biological relevance.
Miniaturisation and automation technologies are drastically shortening assay cycle times, enabling researchers to screen more chemical compounds more quickly while quickly zeroing in on promising candidates. Furthermore, Design of Experiments (DOE) methodologies assist assay developers with optimising their assays with greater accuracy and precision.
Biosensors are devices that convert biological signals into digital information and can detect concentrations of analytes within samples. Medical diagnostics is a common application of biosensors, but they can also be used in fields such as environmental monitoring and food testing. Compared to traditional laboratory techniques, biosensors offer several advantages, including immediate usability without extensive sample preparation and the ability to detect analytes at lower concentrations than other devices. Biosensors typically rely on electrochemical transduction mechanisms and include biological components for identifying analytes, signal amplifiers, and display units. In addition, combining these sensors with other technologies, such as nanotechnology, can further enhance their performance.
There are various approaches to developing biosensors, from cell-based assays to point-of-care applications. Point-of-care biosensors, such as glucose meters for glucose monitoring and fingertip pulse oximeters that monitor oxygen saturation levels and pulse rate, can also be used as part of routine health checks like HIV patient identification.
Other biosensors use antibodies for cell recognition. This type of sensor can identify various microorganisms, including E. coli and S. aureus, with great accuracy; some biosensors can even tell whether or not samples have been contaminated by bacteria.
Depending on the type of sensor being constructed, its composition and sensing characteristics may differ accordingly. For instance, potentiometric biosensors use screen-printed electrodes with conducting polymers coating them with protein analytes attached via enzyme or antibody attachment; when analytes enter this polymer-coated surface area, it causes changes in potential, which are then measured via amplifier.
Biosensors present several issues for manufacturers and users alike, such as being costly to produce and providing inaccurate results. To make them more cost-effective, manufacturers could standardise manufacturing processes to save both time and money in production processes. This would make biosensors more affordable.
Cell-based assays examine how living cells react to drug compounds. These assays are more physiologically relevant than biochemical assays and help researchers better understand cellular dynamics, drug pharmacodynamic effects on living systems, and the development timeframe. Unfortunately, these assays require rigorous validation processes; additionally, they may take more time than expected for development and testing; however, new systems that automate throughput have enabled their use in high-throughput screening (HTS) applications.
Cell-based assay markets in emerging economies are experiencing rapid expansion. This market growth can be attributed to demand for safer and more effective drugs, an expanding pharmaceutical industry and advances in assay technology. A number of companies are creating cell-based assays designed to address various drug development stages, including hit finding, target validation, and lead optimisation.
Assays typically utilise cells grown in a laboratory environment from humans or animals. They can be used to measure various outcomes, including cell proliferation, protein expression, cell death, and cytotoxicity. The type of cells selected for an assay will depend on its desired results. Cell lines often produce reproducible results while being more cost-effective than primary cells, yet they are less physiologically representative than their natural counterparts. Furthermore, many assays require long incubation periods with manual reading; new technologies are now making such processes much faster and more cost-efficient, making these tests even more attractive to pharmaceutical companies.
Cell-based assays can be an invaluable way to assess more than cytotoxicity; they also allow researchers to investigate other biological activities and off-target effects of compounds and make more informed decisions during drug discovery.
Tailoring assay conditions specifically for the application at hand and ensuring easy adjustment are essential for achieving accurate and reproducible results. A software-controlled reagent injector, for example, can deliver correct amounts of reagent into each well of a plate from 384 wells up, eliminating manual intervention while leaving users more time for data analysis and interpretation.
High-throughput screening (HTS) is an experimental technique widely utilised by researchers that allows them to quickly run millions of chemical, genetic, and pharmacological tests for the presence of active molecules or antibodies. HTS helps researchers quickly test thousands of samples for interactions with target molecules or biochemical pathways and may help researchers discover new drug targets or pathways. HTS typically utilises automated equipment that rapidly tests thousands of samples of small-molecular compounds; however, it can also be used with natural products, oligonucleotides, and biological samples. HTS is most often employed within pharmaceutical and biotechnology companies.
An effective drug discovery process begins with high-throughput screening to identify compounds known to bind with specific protein targets, test their ability to modulate target function, and then use this data to develop new drugs capable of targeting these same targets. High-throughput screening has the power to drastically decrease both the handling time and costs associated with drug development projects while mitigating the risk and costs associated with them.
Assessing whether a molecule can be metabolized and excreted by humans through assays referred to as the screening cascade is also vitally important, in addition to testing its binding affinity to its target. Once all screening assays have been passed successfully, ideally any compound that passes this initial screening cascade should move onto additional screening assays, which will enable further screening for activity against other targets or for pharmacological properties such as DMPK and ADME.
UT Southwestern’s High-Throughput Screening Core provides researchers who are creating new small-molecule therapeutics for diseases and conditions with a valuable resource for high-throughput chemical and genome-wide siRNA screens. Working closely with principal investigators at UT Southwestern, this core conducts both high-throughput chemical screens as well as genome-wide siRNA screens to help speed their research efforts.
HTS involves collecting samples in microplates with 384, 1536, or 3456 wells, depending on their nature, before scanning using an electron microscope connected to a computer and analysing its data in order to select candidates for further testing.
Assay development is an essential element of drug discovery. This process involves the identification of tractable chemical compounds using biochemical, molecular, and cell-based approaches; its readouts may have relevance for human health and disease conditions as well as potential candidates in early preclinical stages; late-stage failures have driven costs through the roof, but through diligent assay, development costs can be managed more effectively and discoveries completed more swiftly.
Lignand-binding assays are an integral component of scientific research. They enable scientists to quantify chemical interactions between target proteins and chemical ligands within biological systems ranging from single cells to organs. Ligand-binding assays have applications across many fields, such as pharmacology, toxicology testing, and clinical diagnostics, and are essential in studying complex diseases like cancer or mental illnesses.
Target identification is the foundation of assay development. Depending on your research question, targets may range from proteins or even genes themselves; target identification requires an in-depth knowledge of all molecular and cellular mechanisms involved with disease as well as genomic techniques that allow data gathering.
Once they’ve identified a target, assay developers can design an assay to measure it. This may involve various methods, like ELISA or electrochemiluminescence assays. When selecting complex sample types like serum, plasma, or blood samples that may contain various molecules that interfere with assay results, it is critical that assay developers select and optimise appropriate assays according to each type of sample type containing such molecules; it may require multiple iterations of assay development before finding success with one assay method over another.
Optimized assays effectively test new compounds. Assays that meet these standards should detect small variations in target molecules with ease while still offering good linearity; additional consideration should also be made regarding sample recovery and stability.
Not only is optimising assays important, but creating an analysis workflow is equally essential to ensure reliable and repeatable results and reduce repeat experiments. A good workflow includes protocols for data collection and interpretation as well as outlining expected results; this will help researchers avoid biases or errors that could misinterpret assay data and lead to misinterpretation of it.