High-throughput screening is a regular approach available for identitying new lead compounds for the growing validated drug targets in drug screening. However, it has also introduced a large number of peculiar molecules which interfere drug screening. Pan assay interference compounds (PAINS) interfere with the progress of drug screening in various ways, such as interfering with a biochemical assay, modifying the protein, aggregate-based inhibitors and so on. So it is of vital significance to remove them. This paper has consulted the concept, category of PAINS and reviewed the way of PAINS interfering and the countermeasures to cope with them to direct the approach of high through screening and improve the hits percent.
Drug Discovery ; High-Throughput Screening Assays ; methods

In vitro compartmentalization (IVC) links genotype and phenotype by compartmentalizing individual genes (including expression system) or cells into a micro-droplet reaction region. Combined with fluorescence-activated cell sorting (FACS), it can detect and separate single droplets in ultra-high throughput. IVC-FACS screening method has been widely used in protein engineering, enzyme directed evolution, etc. However, it is difficult to control the homogeneity of droplet size by mechanical dispersion method in previous studies, which seriously affects the quantitative detection of droplets and reduces the efficiency and accuracy of this screening method. With the rapid development of microfluidic chip manufacturing technology, the microfluidic chip-based methods for droplet generation are becoming more efficient and controllable. In this study, firstly, the water-in-oil (W/O) single-layer droplet generation chip was used to prepare single-layer monodisperse W1/O droplets at a high generation frequency, and then the W1/O droplets were reinjected into water-in-oil-in-water (W/O/W) double-layer droplet generation chip to prepare uniform W1/O/W2 double-layer emulsion droplets. By optimizing the flow rate and ratio of the oil and water phases, a single-layer micro-droplet can be generated with a diameter range from 15.4 to 23.2 μm and remain stable for several days under normal incubation. Then the single-layer droplets were reinjected into the double emulsion generation chip. By adjusting the flow rate of drop phase, oil phase and water phase, the double-layer emulsion droplets with a diameter range from 30 to 100 μm at a rate of 1 000 droplets/s could be obtained. Escherichia coli embedded in the double-layer emulsion droplets could be cultured and induced for protein expression. This study lays a foundation for the establishment of a high-throughput screening method based on the droplet and flow cytometry.
Emulsions ; Flow Cytometry ; High-Throughput Screening Assays ; Microfluidics ; methods

Industrial bioprocess is one of the most important research fields supports the promoting of biological manufacturing industry in China, and guarantees the implementation of bioscience and biotechnology research results into the industrial applications. For improving the interconnection between academic researchers and industrial stuffs and pushing research achievement into industrial implementation, bioprocess modelling and control committee of Chinese Society for Microbiology organized two tandem conferences separately in 2012 and 2014 on the topic of "Industrial bioprocess technology", focusing mainly technique front of industrial bioprocess. A special session on industrial technique applications was hold to stimulate cooperation. The conference received many good submissions from academic and industrial sectors. This special issue is based on selected excellent papers from the submissions, together with free submissions. The special issue consists of reviews and original papers, mainly involving the aspects closely related to the bio-industrial sectors including, i) high yield strain constructing and high throughput screening; ii) optimization and modification of industrial enzymes, and iii) bioprocess modelling and high efficient scale-up method.
China ; Congresses as Topic ; Enzymes ; biosynthesis ; Fermentation ; High-Throughput Screening Assays ; Industrial Microbiology ; methods ; Societies, Scientific

We have developed a rapid and high throughput lipase-ANS (8-Anilino-l-naphthalenesulfonic acid) assay to evaluate the thermo-stability of lipases based on the ANS fluorescence signal's increasing and shifting when this small fluorescence probes binds to lipase. The testing lipase samples were incubated at a temperature range of 25 degrees C to 65 degrees C for 30 min before mixed with ANS solution (0.20 mg/mL lipase and 0.05 mmol/L ANS in the buffer of 20 mmol/L Tris-HCl, 100 mmol/L NaCl, pH 7.2) in a cuvette or microplate. Fluorescence signals of the samples were measured at EX 378 nm, EM 465 nm with a fluorescence photometer or a plate reader, and Tm was calculated with the software of GraphPad Prism5.0. The Tm values of several mutants of Penicillium expansum lipase (PEL) were measured with this ANS assay and conventional method simultaneously and the results show that Tm values are comparative and consistent between these methods, suggesting that the lipase-ANS assay is a reliable, rapid and high throughput method for lipase thermo-stability measurement.
Anilino Naphthalenesulfonates ; chemistry ; Enzyme Stability ; High-Throughput Screening Assays ; methods ; Hot Temperature ; Lipase ; metabolism ; Spectrometry, Fluorescence

As an efficient and promising protein engineering strategy, directed evolution includes the construction of mutant libraries and screening of desirable mutants. A rapid and high-throughput screening method has played a critical role in the successful application of directed evolution strategy. We reviewed several high-throughput screening tools which have great potential to be applied in directed evolution. The development of powerful high-throughput screening tools will make great contributions to the advancement of protein engineering.
Directed Molecular Evolution ; methods ; High-Throughput Screening Assays ; methods ; Mutagenesis, Site-Directed ; methods ; Mutant Proteins ; genetics ; Protein Engineering ; methods

The qualitative and quantitative analysis on traditional Chinese medicine and formula components can be made by chemical and instrumental analysis methods. Of both, the instrumental analysis methods play a dominant role, including HPLC, HPLC-MS, HPLC-NMR, GC, GC-MS, biochemical and biological effect. But because traditional Chinese medicines and formula have complicated components, chemical methods are so unspecific that they shall be used less or with caution. While instrumental analysis methods are so specific that they are appropriate for analyzing complicated single component. The analysis techniques for multiple components of traditional Chinese medicines and formula focus on fingerprints, but all of these analysis techniques are limited by the pre-requisite of separation and the lack of general-purpose detectors and therefore being hard to realize the determination of all components of traditional Chinese medicines and formula. In the natural world, however, organisms identify native and alien components through specificity and non-specificity of clusters decided by antigens and antibodies. For example, components of traditional Chinese medicines are directly or indirectly synthesized into antigens and injected into animals, in order to generate specific antibodies and then collect cross reaction information of these components to specific antibodies. As for components without cross reaction, their contents shall be directly read out on the basis of the inhibition rate curve of competitive reaction for specificity of antigens and antibodies. Besides, a cross inhibition rate matrix shall be established first, and them a multiple regression linear equation between cross component concentration or concentration logarithm and inhibition rate by labeling the immunity competitive reaction between antibodies and haptens of traditional Chinese medicine and compound components, and then solved to obtain concentration of each component. The two results are combined to establish the synthetic immunity chip method for traditional Chinese medicine and formula components.
Animals ; Chemistry, Pharmaceutical ; Drugs, Chinese Herbal ; chemistry ; High-Throughput Screening Assays ; methods ; Humans ; Immunohistochemistry ; methods ; Vaccines, Synthetic ; chemistry

Cytometric bead array (CBA) is a new analytical technique, which can achieve real-time and rapid detection of targeted components in a small amount of sample. With many advantages of high throughput screening, high specificity and sensitivity, low cost, easy operation and good repeatability, this CBA technique has been widely used for the detection of various components in foods, agricultural products and environmental samples. Recently, it has got significant development in rapid detection of small molecules. This review briefly introduced the theory of CBA technique, summarized the application in the analysis of small molecules, such as mycotoxins, pesticide residues, shellfish toxins, and then prospected the application of trace small molecules detection in the complex matrices of traditional Chinese medicine and the development trend of it.
Drug Contamination ; High-Throughput Screening Assays ; instrumentation ; methods ; Immunoassay ; instrumentation ; methods ; Microspheres ; Pesticides ; analysis ; Toxins, Biological ; analysis

Metagenomes from uncultured microorganisms are rich resources for novel enzyme genes. The methods used to screen the metagenomic libraries fall into two categories, which are based on sequence or function of the enzymes. The sequence-based approaches rely on the known sequences of the target gene families. In contrast, the function-based approaches do not involve the incorporation of metagenomic sequencing data and, therefore, may lead to the discovery of novel gene sequences with desired functions. In this review, we discuss the function-based screening strategies that have been used in the identification of enzymes from metagenomes. Because of its simplicity, agar plate screening is most commonly used in the identification of novel enzymes with diverse functions. Other screening methods with higher sensitivity are also employed, such as microtiter plate screening. Furthermore, several ultra-high-throughput methods were developed to deal with large metagenomic libraries. Among these are the FACS-based screening, droplet-based screening, and the in vivo reporter-based screening methods. The application of these novel screening strategies has increased the chance for the discovery of novel enzyme genes.
Animals ; Bacteria ; enzymology ; Enzymes ; genetics ; Gene Library ; High-Throughput Screening Assays ; methods ; Metagenome ; genetics ; Metagenomics ; methods ; Plants ; enzymology

Diagnostic Imaging ; methods ; Genes, Neoplasm ; High-Throughput Screening Assays ; Humans ; Molecular Diagnostic Techniques ; Molecular Targeted Therapy ; Neoplasms ; genetics ; pathology ; therapy ; Pathology, Molecular ; methods ; Precision Medicine ; methods

OBJECTIVETo establish an in vitro screening model for steroid 5 alpha-reductase inhibitors using the microplate reader.

METHODSSteroid 5 alpha-reductase was obtained from the liver of female rats, an in vitro screening model for steroid 5 alpha-reductase inhibitors established using the 96-well plate and microplate reader after determination of the enzymatic activity, and the reliability of the model verified with the known 5 alpha-reductase inhibitors epristeride and finasteride. Added to the 96-well plate were the final concentrations of testosterone (0-40 micromol/L), NADPH (22 micromol/L), epristeride (0-60 nmol/L) or finasteride (0-60 nmol/ L) and steroid 5 alpha-reductase (20 microl), the total volume of each well adjusted to 200 microl with Tris-Hcl buffer. The 96-well plate was placed in the microplate reader, mixed and incubated at 37 degrees C, followed by detection of the A340nm value at 0 and 10 min and analysis of the data.

RESULTSThe Km value of steroid 5 alpha-reductase was 3.794 micromol/L, with a Vmax of 0.271 micromol/(L. min). The Ki of epristeride was 148.2 nmol/L, with an IC50 of 31.5 nmol/L, and the enzymatic reaction kinetic curve suggested that epristeride was an uncompetitive enzyme inhibitor. The Ki of finasteride was 158. 8 nmol/L, with an IC50 of 13.6 nmol/L. The enzymatic reaction kinetic curve showed that both epristeride and finasteride were competitive enzyme inhibitors, similar to those reported in the published literature.

CONCLUSIONA screening model was successfully established, which could rapidly and effectively screen steroid 5 alpha-reductase inhibitors in vitro.

5-alpha Reductase Inhibitors ; analysis ; Animals ; Drug Evaluation, Preclinical ; methods ; Female ; High-Throughput Screening Assays ; instrumentation ; methods ; Immunoenzyme Techniques ; Rats ; Rats, Sprague-Dawley