Microfluidic system for high-throughput immunoglobulin-E analysis from clinical serum samples

Reversed-phase allergen microarrays on optical discs for multiplexed diagnostics of food allergies

A high percentage of the population suffers from multiple food allergies justifying  the importance of reliable diagnostic methods. Single-analyte solutions based on the determination of specific immunoglobulins E (sIgE) are safe and fast but are generally time-consuming and expensive. Thus sustainable microanalytical methods that provide multianalyte profiling information are highly demanded. This work presents the in vitro biosensing of specific IgE levels based on a reversed-phase allergen array. The approach consists of optical biosensing supported by direct multiplex immunoassays and on-disc technology. It identifies 12 sIgE associated with food allergies in a single analysis with a low serum sample volume (25 µL). After processing captured images, specific signals for each target biomarker correlate to their concentration. The assay analytically performs well with 0.3 IU/mL and 0.41 IU/mL as the detection and quantification limits in serum, respectively. This novel method achieves excellent clinical specificity (100%) and high sensitivity (91.1%), considering the diagnosis obtained by clinical history and ImmunoCAP analysis. The results demonstrate that microanalytical systems based on allergen arrays can potentially diagnose multiple food allergies and are easily implemented in primary care laboratory settings.

Flow-based System: A Highly Efficient Tool Speeds Up Data Production and Improves Analytical Performance

In this review, we cite references from the period between 2015 and 2020 related to the use of a flow-based system as a tool to obtain a modern analytical system for speeding up data production and improving performance. Based on a great deal of concepts for automatic systems, there are several research groups introduced in the development of flow-based systems to increase sample throughput while retaining the reproducibility and repeatability as well as to propose new platforms of flow-based systems, such as microfluidic chip and paper-based devices. Additionally, to apply a developed system for on-site analysis is one of the key features for development. We believe that this review will be very interested and useful for readers because of its impact on developing novel analytical systems. The content of the review is categorized following their applications including quality control and food safety, clinical diagnostics, environmental monitoring and miscellaneous.

Prospects and Opportunities for Microsystems and Microfluidic Devices in the Field of Otorhinolaryngology

Microfluidic systems can be used to control picoliter to microliter volumes in ways not possible with other methods of fluid handling. In recent years, the field of microfluidics has grown rapidly, with microfluidic devices offering possibilities to impact biology and medicine. Microfluidic devices populated with human cells have the potential to mimic the physiological functions of tissues and organs in a three-dimensional microenvironment and enable the study of mechanisms of human diseases, drug discovery and the practice of personalized medicine. In the field of otorhinolaryngology, various types of microfluidic systems have already been introduced to study organ physiology, diagnose diseases, and evaluate therapeutic efficacy. Therefore, microfluidic technologies can be implemented at all levels of otorhinolaryngology. This review is intended to promote understanding of microfluidic properties and introduce the recent literature on application of microfluidic-related devices in the field of otorhinolaryngology.

An automatic integrated microfluidic system for allergy microarray chips

Billions of people suffer from allergies, though in many cases, the source allergen is unknown. If one knows which allergens to avoid, this would result in an improved quality of life. Since a rapid, high-throughput, automatic allergen detection method is of great need, an integrated system combining microfluidic techniques and microarray chips has been developed herein to automate the allergen detection process. The developed microfluidic system could automatically carry out the entire procedure such as reagent incubation, hybridization, transport, and washing without any intermediate step. The microarray chip could be easily detached from the microfluidic chip afterwards, enabling it to be read under a fluorescence scanner. The experimental results indicated that the developed microfluidic system can automatically perform all the incubation processes, including hybridization, reagent transportation, and washing. It is worth noting that active mixing has been applied in the present study which is different from our previous study using micro-channels for passive incubation. Comparable results to a conventional benchtop approach were obtained in ∼30% less time with ∼25% less samples/reagents. Similar results were also demonstrated while detecting immunoglobulin E samples. The developed system could therefore provide a rapid, reliable, and automated approach for detecting allergen-specific antibodies in human serum.

Stacking chip for quantitative bioanalysis

This paper describes a microwell-based microdevice for performing quantitative bioanalysis. This microdevice combined the passive pumping by degassed polydimethylsiloxane (PDMS) with serial operations including solution dispensing, plates splitting and plates stacking. We name this microdevice "stacking chip". To use the stacking chip in quantitative bioanalysis, nanoliter solutions were first dispensed into the microwells through the degassed PDMS microchannels. Next, we split the microwell and microchannel plates assisted by the application of one drop of silicone oil, which resulted in a microwell array containing the reagent solutions. Microreactor arrays were formed by stacking the two microwell arrays containing the reagent solutions. With this microdevice, the enzymatic kinetics of alkaline phosphatase during the dissociation of the fluorescein diphosphate was measured and analyzed by the Michaelis-Menten model. The stacking chip is simple to fabricate and operate, and amenable to automation for high throughput analysis.