ABSTRACT
The early diagnosis of cancer is aimed at intervention, as far as possible in the early stage of the treatment of cancer, thereby reducing the suffering and economic burden of the patient. Circulating tumor cells (CTCs) are tumor cells that fall from the malignant tumor into the circulatory system and form cancer metastasis when they migrate to distant organs. The detection and identification of CTCs is important for the study, monitoring and intervention of cancer metastasis processes. However, the amount of CTCs in the blood is extremely rare, and the environment in the blood is complex, which poses a huge technical challenge for its screening and analysis. Various methods have been developed to enrich CTCs from blood samples of cancer patients. Among them, microfluidic technology has great advantages in the field of CTC detection.
ABSTRACT
Miniaturized, integrated and automated microfluidic chips provided a new solution for clinical laboratory technology. However, microfluidic chips still require accessory devices to read, analyze and display results. The portable, widely-used and multi-functional smartphones have provided a simple, portable, cost-effective, and easy-to-use platform for microfluidic chips. The combination of the two technologies is expected to become the next-generation of diagnostic methods, especially the important research direction of point-of-care testing (POCT).
ABSTRACT
The early diagnosis of cancer is aimed at intervention, as far as possible in the early stage of the treatment of cancer, thereby reducing the suffering and economic burden of the patient. Circulating tumor cells (CTCs) are tumor cells that fall from the malignant tumor into the circulatory system and form cancer metastasis when they migrate to distant organs. The detection and identification of CTCs is important for the study, monitoring and intervention of cancer metastasis processes. However, the amount of CTCs in the blood is extremely rare, and the environment in the blood is complex, which poses a huge technical challenge for its screening and analysis. Various methods have been developed to enrich CTCs from blood samples of cancer patients. Among them, microfluidic technology has great advantages in the field of CTC detection.
ABSTRACT
Miniaturized, integrated and automated microfluidic chips provided a new solution for clinical laboratory technology. However, microfluidic chips still require accessory devices to read, analyze and display results. The portable, widely-used and multi-functional smartphones have provided a simple, portable, cost-effective, and easy-to-use platform for microfluidic chips. The combination of the two technologies is expected to become the next-generation of diagnostic methods, especially the important research direction of point-of-care testing (POCT).
ABSTRACT
Circulating tumor cells ( CTCs ) exists in peripheral blood of patients with a variety of malignant tumors , the accurate detection of CTCs helps early detection of cancer , and can be used to guide individualized treatment of cancer patients , rapid assessment of tumor chemotherapy drugs and detection of tumor recurrence .However , the CTCs in peripheral blood of cancer patients were extremely low , their detection requires efficient and specific enrichment and separation methods .The new microfluidic technology can accurately control the microliquid preciously , combined with the immunomagnetic separation technology , has been applied in detecting CTCs , which can save the blood samples of CTCs , has the advantages of simple operation , fast sorting speed , high specificity and high purity .
ABSTRACT
The efficient characterization of genetic and epigenetic alterations in oncology requires highly sensitive and specific high throughput procedures.However, the necessary level of sensitivity and specificity were previously unreachable using conventional testing procedures.By partitioning individual target molecules within separated compartments, digital PCR ( dPCR ) could allow to overcome such limitations and detect with unprecedented accuracy very rare sequences.In such procedure, the sample is diluted such that each individual compartment will contain no more than one target sequences.The assay provides an absolute value and quantitative data.The recent coupling of dPCR procedure with microfluidic systems in commercial platforms should make droplet based digital PCR an essential tool for the management of patients with cancer.Applications range from the analysis of tumor heterogeneity to the analysis of body effluents.Droplet based digital PCR is also particularly suited for the increasing field of liquid biopsy analysis.
ABSTRACT
Microfluidics-based digital PCR depends on microfluidic chip to split PCR reaction mixture into many tiny equal-volume units.Quantitative assessment of target DNA template can be obtained by counting the number of fluorescence-positive units after thermocycling.Microfluidics-based digital PCR exhibits many advantages including absolute quantification, high sensitivity and accuracy, and shows great promise in a variety of applications, such as infectious diseases diagnose, early cancer detection and prenatal diagnose. There are already several microfludics-based digital PCR products produced from sereval companies.It is believed that as the technology improves, microfluidics-based digital PCR will find broader applications and become the next-generation tool for genetic tests.
ABSTRACT
Microfluidic chip exhibit a great promising development in clinical diagnosis and disease screening due to their advantages of precise controlling of fluid flow,requirement of mini amount sample,rapid reaction speed and convenient integration.A lot of demonstrations on the diagnostic applications related to genes,proteins,and cells have been reported because of their advantages associated with miniaturization and automation.Here,the applications and developments of on-chip nucleic acid amplification and analysis,protein analysis and detection,cell selection and cell drug screening were discussed.Microfluidic chip can provide an easy integration platform for biomarkers in a high throughput and accurate detection.
ABSTRACT
Major infectious diseases affect human health seriously .In order to prevent , control and treat diseases effectively , the key lies in rapid detection and identification of pathogens .Rapid development and wide application of molecular biological techniques , such as PCR, gene sequencing and bio-chip technology , have greatly improved the prevention , control and treatment of major infectious diseases .The future development trend is to establish an accurate , rapid, high-throughput , portable and intelligent diagnostic technology of molecular biology .
ABSTRACT
Objective A new method for detecting K-ras mutations based liquid chip was used to evaluate K-ras mutations associated with non-small cell lung cancer (NSCLC) patients,to direct the personalized treatment and prognosis evaluation.Methods Take the diagnosis technology research methods,the sensitivity and repeatability of the liquid chip K-ras gene mutation detection method were assessed.A total of 100 NSCLC patients from Nov 2011 to Feb 2012 in Shanghai Chest hospital were included in this study,the fresh tumor tissues were collected for DNA extraction.The 2nd exon 12 and 13 codons,containing 8 K-ras mutations occuring in high frequency were amplified by polymerase chain reaction (PCR),followed by ligation of the PCR products to a series of special probes using ligase detection reaction (LDR),then the PCR-LDR products were analyzed by liquid chip platform.Direct sequencing was applied to compare with the detection results.Results The sensitivity of liquid chip technology detection was 10％-20％,higher than the traditional sequencing method by 1％.Average CV value was 4％-15％ and showed good repeatability.5 K-ras mutations in 100 patients (5％) were detected using multiplex PCR-LDR combined fluid chip methods,including 3 Glyl2Val and 2 Gly12Asp mutations in exon 2.The 5 K-ras mutations were verified accurately by direct sequencing.Conclusions The novel detection method of K-ras mutations based PCRLDR and fluid chip shows high throughput,high sensitivity,good repeatability and the results are reliable and accurate.This method can be used to accurately identified K-ras mutations for NSCLC patients prior to their targeted therapy with TKIs.
ABSTRACT
Objective To develop a phenylketonuria (PKU) screening method based on a compact disk (CD) type microfluidic chip capable of generating reciprocating flow within the microchannels that facilitate rapid DNA hybridization. Methods This microfluidic device consists of a two-layer structure: a polydimethylsiloxane (PDMS) top layer containing 12 DNA hybridization microchannels, and a bottom glass layer with immobilized hydrogel conjugated DNA arrays. The DNA arrays included R243Q, V245V and the blank control probes. When the CD device was spun, the PCR products were driven into the hybridization channel by centrifugal force. When the rotation of the CD device was stopped, capillary force pulled the PCR products solution to flow back to the channel. After the on-chip hybridization, the hybridization signals were captured on a fluorescence microscope. The specificity, detection limitation and reproducibility of this device were evaluated. Thirty DNA samples from pregnant women with suspected PKU were detected by this device.Then the results were compared with DNA sequencing results. Results With the compact disk type microfluidic chip, the hybridization time could be reduced to 15 min, sample consume could be as low as 1. 5 μl and the detection limitation was 0. 7 ng/μl. With the chip based method, samples of PKU patients and healthy controls were detected and the results were consistent with DNA sequencing results. Five different batches of chips and five micro-channels of each chip were selected to test one PKU patients with V245V mutation. All the results were positive, indicating good reproducibility. Four cases of V245V mutation and 1 case of R243Q mutation were found in 30 suspected PKU carried pregnant women. Conclusion The compact disk microfluidic device has advantages of simple, rapid and highly sensitive, thus is well suited to PKU screening.
ABSTRACT
Objectiye To optimize the depth of the microchannel and the time point for sperm collection,and improve the efficiency of sperm screening on a microfluidic device. Methods Microchannels with four different depths of 25, 50, 100 and 200 μm were tested. Mice sperm were added to the inlet of the microchannel. The relative quantity and motility of sperm in the outlet were recorded at different collection times, i.e. ,5, 15, 30 and 60 min. Statistical method one-way ANOVA and appropriate post-hoc testing were applied to analyze differences between different groups, and further to select the best-fit depth of the microchannel and the time point for collection. Results In microchannels with depths of 25, 50, 100 and 200 μm, the sperm motilities measured in each outlet were (85.4 ± 2.3)%, (85.8 ± 5.8)%,( 87. 2 ± 2. 8 ) %, (76. 5 ± 2. 8 ) % respectively with statistical significance ( F = 5.8, P ＜ 0. 05 ). No obvious differences were found among 25-100 μm channels, however the motility dramatically decreased in the 200 μm group. The relative sperm quantities were (5.2 ±2.0)%, (7.2 ±2.5)%,(12.3 ±2.0)%,(7. 7 ± 1.1 ) % respectively with statistical significance ( F = 6. 9, P ＜ 0. 05), which increased with channel depth from 25 to 100 μm,while it decreased in the 200 μm channel Taking 2 indexes into account, 100 μmwas the most fit channel depth for sperm motility screening. The sperm motility in the outlet gradually decreased with time. At the time points of 5, 15, 30 and 60 min after adding sperm, the sperm motilities were (99. 6 ±0. 7)%, (87.2 ±2. 8)%, (79. 3 ±2. 2)% and (62. 6 ±8.0)% respectively with statistical significance ( F = 37. 3, P ＜ 0. 01 ). Yet the relative quantities of sperm in the outlet increased almost three times in this process. At the time points mentioned above, the relative quantities of sperm were (5.8±1.1)%, (10.6 ± 0.9)%, (12.1 ± 1.7)%, (17.9 ± 3.4)% respectively with statistical significance ( F = 17.8, P ＜ 0. 01 ). Thus 15-30 min was the ideal screening time. Conclusion An effective microdevice for sperm screening with optimized depth and collection time period is developed,which may contribute significantly for the screening of healthy sperm on microfluidic chips.