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International Journal of Molecular... May 2021Antibody therapeutics are expanding with promising clinical outcomes, and diverse formats of antibodies are further developed and available for patients of the most... (Review)
Review
Antibody therapeutics are expanding with promising clinical outcomes, and diverse formats of antibodies are further developed and available for patients of the most challenging disease areas. Bispecific antibodies (BsAbs) have several significant advantages over monospecific antibodies by engaging two antigen targets. Due to the complicated mechanism of action, diverse structural variations, and dual-target binding, developing bioassays and other types of assays to characterize BsAbs is challenging. Developing bioassays for BsAbs requires a good understanding of the mechanism of action of the molecule, principles and applications of different bioanalytical methods, and phase-appropriate considerations per regulatory guidelines. Here, we review recent advances and case studies to provide strategies and insights for bioassay development for different types of bispecific molecules.
Topics: Animals; Antibodies, Bispecific; Antigens; Biological Assay; Humans; Immunotherapy
PubMed: 34069573
DOI: 10.3390/ijms22105350 -
Profiles of Drug Substances,... 2021This present review described the validation method of in-vitro bioassay for its application in herbal drug research. Seven sequencing steps that can be taken for... (Review)
Review
This present review described the validation method of in-vitro bioassay for its application in herbal drug research. Seven sequencing steps that can be taken for performing a valid bioassay include: literature survey, sample stability evaluation, Biosystem performance testing, Sample performance evaluation, determination of 50% effective concentration or cytotoxic concentrations, selective index evaluation, and determination of accurate relative potency of sample. Detailed methods and acceptance criteria for each step are described herein. Method calculations of the relative potency of sample using European Pharmacopeia 10.0, 5.3 (2020) were recommended instead of using United States Pharmacopeia 42 (2019). For having reliable data and conclusions, all methods (chemical and bioassay) need to be first validated before any data collection. Absence of any validation method may results in incorrect conclusions and bias.
Topics: Biological Assay; Plant Preparations
PubMed: 33461699
DOI: 10.1016/bs.podrm.2020.07.005 -
Analytical Biochemistry Dec 2023Microarrays are powerful tools for high-throughput bioassays that can extract information from tens of thousands of micro-spots consisting of biomolecules. This... (Review)
Review
Microarrays are powerful tools for high-throughput bioassays that can extract information from tens of thousands of micro-spots consisting of biomolecules. This information is invaluable to many applications, such as drug discovery and disease diagnostics. Different applications of these microarrays need spots of different shapes, sizes, and chemistries to achieve their goals. Micro/nano-fabrication techniques are used to make microarrays with different feature structures and array densities for required assay procedures. Understanding these fabrication methods is essential to creating an effective microarray. The purpose of this article is to critically review fabrication methods used in recent microarray-based bioassay studies. We summarized commonly used microarray fabrication techniques and filled the gap in recent literature on relevant topics. We discussed recent examples of how microarrays were fabricated and used in a variety of bioassays. Specifically, we examined microarray printing, various microlithography techniques, and microfluidics-based microarray fabrication. We evaluated how their application shaped the fabrication methods and compared their performance based on different applications. In the end, we discussed current challenges and outlined potential future directions. This review addressed the gap in literature and provided important insights for choosing appropriate fabrication techniques towards different applications.
Topics: Microarray Analysis; Microfluidics; Biological Assay
PubMed: 37914004
DOI: 10.1016/j.ab.2023.115369 -
Lab on a Chip Aug 2022Digital bioassays based on single-molecule enzyme reactions represent a new class of bioanalytical methods that enable the highly sensitive detection of biomolecules in... (Review)
Review
Digital bioassays based on single-molecule enzyme reactions represent a new class of bioanalytical methods that enable the highly sensitive detection of biomolecules in a quantitative manner. Since the first reports of these methods in the 2000s, there has been significant growth in this new bioanalytical strategy. The principal strategy of this method is to compartmentalize target molecules in micron-sized reactors at the single-molecule level and count the number of microreactors showing positive signals originating from the target molecule. A representative application of digital bioassay is the digital enzyme-linked immunosorbent assay (ELISA). Owing to their versatility, various types of digital ELISAs have been actively developed. In addition, some disease markers and viruses possess catalytic activity, and digital bioassays for such enzymes and viruses have, thus, been developed. Currently, with the emergence of new microreactor technologies, the targets of this methodology are expanding from simple enzymes to more complex systems, such as membrane transporters and cell-free gene expression. In addition, multiplex or multiparametric digital bioassays have been developed to assess precisely the heterogeneities in sample molecules/systems that are obscured by ensemble measurements. In this review, we first introduce the basic concepts of digital bioassays and introduce a range of digital bioassays. Finally, we discuss the perspectives of new classes of digital bioassays and emerging fields based on digital bioassay technology.
Topics: Biological Assay; Enzyme Assays; Enzyme-Linked Immunosorbent Assay; Technology
PubMed: 35861036
DOI: 10.1039/d2lc00223j -
International Journal of Biological... Mar 2019Non-invasive diagnosis of cancer is often the key to effective treatment and patient survival. Saliva as a multi-constituent oral fluid comprises various disease... (Review)
Review
Non-invasive diagnosis of cancer is often the key to effective treatment and patient survival. Saliva as a multi-constituent oral fluid comprises various disease signaling biomarkers, holds great potential for early-stage cancer diagnostics with cost-effective and easy collection, storage, transport and processing. Therefore, detection of biomarkers and proteins in the saliva samples is highly demand. The current review was performed using reliable internet database (mainly PubMed) to provide an overview of the most recent developments on non-invasive diagnosis of cancers in saliva and highlights main challenges and future prospects in sensing of the salivary biomarkers. The conventional detection methods of cancer biomarkers in saliva is discussed in the paper, however, the main focus is on non-invasive diagnosis of cancers in saliva using immunosensing (electrochemical, optical, piezoelectric), DNA based sensors, aptasensors and peptide based bio-assays The reviewed literature revealed that non-invasive cancer detection methods using the mentioned biosensors and without any processing of saliva sample offers a quick, sensitive, specific and cost effective analytical tool. Besides, salivary based detection methods can be used for simultaneous detection of panels of disease specific biomarkers in a real time manner or as home testing kits in near future.
Topics: Aptamers, Nucleotide; Aptamers, Peptide; Biological Assay; Biomarkers, Tumor; Biosensing Techniques; Early Detection of Cancer; Electrochemical Techniques; Humans; Immunoassay; Neoplasms; Saliva; Salivary Proteins and Peptides
PubMed: 30513307
DOI: 10.1016/j.ijbiomac.2018.11.277 -
Angewandte Chemie (International Ed. in... Feb 2023A single-molecule electrochemiluminescence bioassay is developed here which allows imaging and direct quantification of single biomolecules. Imaging single biomolecules...
A single-molecule electrochemiluminescence bioassay is developed here which allows imaging and direct quantification of single biomolecules. Imaging single biomolecules is realized by localizing the electrochemiluminescence events of the labeled molecules. Such an imaging system allows mapping the spatial distribution of biomolecules with electrochemiluminescence and contains quantitative single-molecule insights. We further quantify biomolecules by spatiotemporally merging the repeated reactions at one molecule site and then counting the clustered molecules. The proposed single-molecule electrochemiluminescence bioassay is used to detect carcinoembryonic antigen, showing a limit of detection of 67 attomole concentration which is 10 000 times better than conventional electrochemiluminescence bioassays. This spatial resolution and sensitivity enable single-molecule electrochemiluminescence bioassay a new toolbox for both specific bioimaging and ultrasensitive quantitative analysis.
Topics: Nanotechnology; Diagnostic Imaging; Biological Assay
PubMed: 36504245
DOI: 10.1002/anie.202214419 -
Gut Feb 1982An in vitro bioassay for cholecystokinin which is superior to the previously described in vivo assays has been properly validated mathematically. The specificity of the... (Comparative Study)
Comparative Study
An in vitro bioassay for cholecystokinin which is superior to the previously described in vivo assays has been properly validated mathematically. The specificity of the assay has been assessed by measuring the potency of other polypeptides which share the same C-terminal pentapeptide sequence with cholecystokinin (gastrin, caerulin, octapeptide of cholecystokinin, and pentagastrin). The assay is shown to be quite specific for cholecystokinin. Secretin does not interfere with the assay. Comparison of the relative potency of the two commercially available preparations of cholecystokinin indicates that the two major units of measurement are almost identical in cholecystokinetic potency. One Crick Harper Raper unit of cholecystokinin (Boots) is equivalent to 1.22 +/- 0.12 Ivy dog units of cholecystokinin (Karolinska Institute). The lower limit of sensitivity for the assay was 2.5m IDU/ml.
Topics: Biological Assay; Cholecystokinin; Cross Reactions; Peptides
PubMed: 7068037
DOI: 10.1136/gut.23.2.146 -
Sensors (Basel, Switzerland) 2012Accurate prediction of the adverse effects of test compounds on living systems, detection of toxic thresholds, and expansion of experimental data sets to include... (Review)
Review
Accurate prediction of the adverse effects of test compounds on living systems, detection of toxic thresholds, and expansion of experimental data sets to include multiple toxicity end-point analysis are required for any robust screening regime. Alamar Blue is an important redox indicator that is used to evaluate metabolic function and cellular health. The Alamar Blue bioassay has been utilized over the past 50 years to assess cell viability and cytotoxicity in a range of biological and environmental systems and in a number of cell types including bacteria, yeast, fungi, protozoa and cultured mammalian and piscine cells. It offers several advantages over other metabolic indicators and other cytotoxicity assays. However, as with any bioassay, suitability must be determined for each application and cell model. This review seeks to highlight many of the important considerations involved in assay use and design in addition to the potential pitfalls.
Topics: Animals; Biological Assay; Cell Survival; Coloring Agents; Humans; Indicators and Reagents; Oxazines; Xanthenes
PubMed: 23112716
DOI: 10.3390/s120912347 -
Regulatory Toxicology and Pharmacology... Feb 1995The proper design of carcinogenicity bioassays is critical to the interpretation and use of the data that emerge upon its completion. This paper explores some of the... (Review)
Review
The proper design of carcinogenicity bioassays is critical to the interpretation and use of the data that emerge upon its completion. This paper explores some of the scientific underpinnings that need to be considered when designing bioassays. It also discusses new approaches that can be used to improve dose setting and interpretation of bioassay results. Critical information that determines the shape of the dose-response curve include the molecular dose of the agent that binds to DNA, cell proliferation, and cell death. Such data can be used to replace default assumptions and improve the extrapolation of risk from animal studies to humans.
Topics: Animals; Apoptosis; Biological Assay; Carcinogenicity Tests; Cell Division; Dose-Response Relationship, Drug; Female; Humans; Male; Maximum Allowable Concentration; Mice; Models, Biological; Molecular Epidemiology; Rats; Rats, Inbred F344; Risk Assessment
PubMed: 7784635
DOI: 10.1006/rtph.1995.1008 -
Drug Metabolism Reviews 1996Bioassays that include various types of discontinuous exposure to carcinogens are somewhat rare and are far from routine. However, discontinuous-dosing groups represent... (Review)
Review
Bioassays that include various types of discontinuous exposure to carcinogens are somewhat rare and are far from routine. However, discontinuous-dosing groups represent a valuable enhancement of the ordinary bioassay design. My hope is that efforts to include discontinuous-exposure groups in cancer-bioassays will become widespread, and that discontinuous-dosing designs will eventually be a matter of routine. To me, such designs represent an easy (although perhaps costly) way to increase the sophistication of the tumor incidence data for model fitting, and to provide valuable data for validating (or perhaps invalidating) postulated mathematical models of the cancer process. Certainly discontinuous-dosing data at least provide a valuable ancillary resource to be utilized along with data on postulated mechanisms in the effort to implement biologically based models of the cancer process for quantitative risk assessment. Such data might even be indispensible.
Topics: Animals; Biological Assay; Carcinogens; Dose-Response Relationship, Drug; Humans; Models, Biological; Neoplasms; Risk Assessment
PubMed: 8744598
DOI: 10.3109/03602539608994001