The present invention includes methods of enriching rare cells, such as cancer cells, from biological samples, such as blood samples. The methods include performing at least one debulking step on a blood sample and selectively removing at least one type undesirable component from the blood sample to obtain a blood sample that is enriched in a rare cell of interest. In some embodiments magnetic beads coupled to specific binding members are used to selectively removed components.

Methods and compositions for separating rare cells from fluid samples

PCR has been widely used in different fields including molecular biology, pathogen detection, medical diagnosis, food detection and etc. However, the difficulty of promoting PCR in on-site point-of-care testing reflects on challenges relative to its speed, convenience, complexity, and even cost. With the emerging state-of-art of microfluidics, rapid PCR can be achieved with more flexible ways in micro-reactors. PCR plays a critical role in the detection of SARS-CoV-2. Under this special background of COVID-19 pandemic, this review focuses on the latest rapid microfluidic PCR. Rapid PCR is concluded in two main features, including the reactor (type, size, material) and the implementation of thermal cycling. Especially, the compromise between speed and sensitivity with microfluidic PCR is explored based on the system ratio of (thermal cycling time)/(reactor size). Representative applications about the detection of pathogens and SARS-CoV-2 viruses based on rapid PCR or other isothermal amplification are discussed as well.

Rapid PCR Powered by Microfluidics: A Quick Review Under the Background of COVID-19 Pandemic.

The point-of-care-testing of nucleic acids by chip, cartridge and paper sensors

Assays for the molecular detection of nucleic acids are typically constrained by the level of multiplexing (this is the case for the quantitative polymerase chain reaction (qPCR) and for isothermal amplification), turnaround times (as with microarrays and next-generation sequencing), quantification accuracy (isothermal amplification, microarrays and nanopore sequencing) or specificity for single-nucleotide differences (microarrays and nanopore sequencing). Here we show that a portable and battery-powered PCR assay performed in a toroidal convection chamber housing a microarray of fluorescently quenched oligonucleotide probes allows for the rapid and sensitive quantification of multiple DNA targets with single-nucleotide discrimination. The assay offers a limit of detection of 10 DNA copies within 30 min of turnaround time and a dynamic range spanning 4 orders of magnitude of DNA concentration, and we show its performance by detecting 20 genomic loci and 30 single-nucleotide polymorphisms in human genomic DNA samples, and 15 bacterial species in clinical isolates. Portable devices for the fast and highly multiplexed detection of nucleic acids may offer advantages in point-of-care diagnostics. A portable PCR assay performed in a toroidal convection chamber housing an array of fluorescently quenched oligonucleotide probes allows for the rapid quantification of multiple DNA targets with single-nucleotide discrimination.

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Highly multiplexed rapid DNA detection with single-nucleotide specificity via convective PCR in a portable device.

A rotary multi-positioned cloth/paper hybrid microfluidic device for simultaneous fluorescence sensing of mercury and lead ions by using ion imprinted technologies

Nucleic acid detection is of great significance in clinical diagnosis, environmental monitoring and food safety. Compared with the traditional nucleic acid amplification detection method, surface plasmon resonance (SPR) sensing technology has the advantages of being label-free, having simple operation, and providing real-time detection. However, the angle scanning system in many SPR angle modulation detection applications usually requires a high-resolution stepper motor and complex mechanical structure to adjust the angle. In this paper, a portable multi-angle scanning SPR sensor was designed. The sensor only uses one stepping motor to rotate a belt, and the belt pulls the mechanical linkages of incident light and reflected light to move in opposite directions for achieving the SPR angle scanning mode that keeps the incident angle and reflected angle equal. The sensor has an angle scanning accuracy of 0.002°, response sensitivity of 3.72 × 10-6 RIU (refractive index unit), and an angle scanning range of 30°-74°. The overall size of the system is only 480 mm × 150 mm × 180 mm. The portable SPR sensor was used to detect nucleic acid hybridization on a gold film chip modified with bovine serum albumin (BSA). The result revealed that the sensor had high sensitivity and fast response, and could successfully accomplish the hybridization detection of target DNA solution of 0.01 μmol/mL.

Development of a Portable SPR Sensor for Nucleic Acid Detection.

Free convective PCR: From principle study to commercial applications-A critical review

The invention discloses an integrated micro-fluidic chip system, which comprises a micro-fluidic chip, a light source unit, a sample introduction unit, a detection unit and a communication unit, wherein the micro-fluidic chip is connected with the light source unit through optical fibers and connected with the sample introduction unit through a hose; and the communication unit is electrically connected with the detection unit, the light source unit and the sample introduction unit When used for detecting biochemical substances having a fluorescence response property in a fluid sample, the system can solve the problems in prior art such as time consumption, large reagent and sample consumption, complex operation and the like, can realize fluorescence detection under various conditions, hasthe advantages of high integration, quick analysis, high flexibility, little sample consumption, simple operation, quantitative analysis, online real-time detection and the like, has a compiling control degree that allows for combined use with a computer, independent operation, and can be used as a sensor unit in a wireless sensor network

Integrated micro-fluidic chip system

Epilepsy is a common neurological disorder. There is still a lack of methods to accurately detect cortical activity and locate lesions. In this work, a flexible electrocorticography (ECoG) electrode array based on polydimethylsiloxane (PDMS)-parylene was fabricated to detect epileptiform activity under glutamate (Glu) and gamma-aminobutyric acid (GABA) modulation on primary somatosensory cortex of rats. The electrode with a thickness of 20 μm has good flexibility to establish reliable contact with the cortex. Fourteen recording sites with a diameter of 60 μm are modified by electroplating platinum black nanoparticles, which effectively improve the performance with lower impedance, obtaining a sensitive sensing interface. The electrode enables real-time capturing changes in neural activity under drug modulation. Under Glu modulation, neuronal populations showed abnormal excitability, manifested as hypsarrhythmia rhythm and continuous or periodic spike wave epileptiform activity, with power increasing significantly. Under GABA modulation, the excitement was inhibited, with amplitude and power reduced to normal. The flexible ECoG electrode array could monitor cortical activity, providing us with an effective tool for further studying epilepsy and locating lesions.

Flexible Electrocorticography Electrode Array for Epileptiform Electrical Activity Recording under Glutamate and GABA Modulation on the Primary Somatosensory Cortex of Rats.

Lulu Zhang

Papers

Rapid PCR Powered by Microfluidics: A Quick Review Under the Background of COVID-19 Pandemic.

Development of a Portable SPR Sensor for Nucleic Acid Detection.

Free convective PCR: From principle study to commercial applications-A critical review

Integrated micro-fluidic chip system

Flexible Electrocorticography Electrode Array for Epileptiform Electrical Activity Recording under Glutamate and GABA Modulation on the Primary Somatosensory Cortex of Rats.