多粒子纠缠态QTDM通信方案及QMU协议

分析了未知的三个三态粒子纠缠态的隐形传送过程,结合纠缠源的特性,提出了量子信道时分复用方案.同时还提出了一种可传送多粒子纠缠态的量子时分多路通信方案和量子多用户协议.研究结果表明,该方案与采用BB84协议的量子通信系统相比,不仅能够实现量子多用户安全保密通信,而且误码率低.     

Performance of Fluorescent Labels in Sedimentation Bead Arrays—A Comparison Study

An extensive study is described to identify the most suitable fluorescent label in magnetic microsphere sedimentation arrays. The investigated fluorescent labels, commonly used in multiplex analysis, include organic dyes, (fluorescein, Alexa488, Cy5) fluorescent proteins (R-Phycoerythrin, Allophycocyanine, PBXL-3) polymer nanoparticles (FluoSpheres, PD-Pt) and semiconductor nanocrystals (Quantum dots). DNA hybridization assays on magnetic microspheres were applied as model systems to reveal label performance. The fluorescent labels were characterized under optimized conditions regarding signal intensity, non-specific binding and photo-stability. The advantages and drawbacks of individual labels are discussed. The limit of detection and dynamic ranges are determined to compare the performance of selected labels. Detection limits of 2 × 10⁻¹⁰ mol/L are found for the determination of oligonucleotides using PBXl-3 as label, which is comparable with typical flow cytometer systems. The results and protocols are highly valuable for any type of bead based assays and can be easily transferred.     

Pyrosequencing‐based strategy for a successful SNP detection in two hypervariable regions: HV‐I/HV‐II of the human mitochondrial displacement loop

Forensic analysis of mitochondrial displacement loop (D‐loop) sequences using Sanger sequencing or SNP detection by minisequencing is well established. Pyrosequencing has become an important alternative because it enables high‐throughput analysis and the quantification of individual mitochondrial DNAs (mtDNAs) in samples originating from more than one individual. DNA typing of the mitochondrial D‐loop region is usually the method of choice if STR analysis fails because of trace amounts of DNA and/or extensive degradation. The main aim of the present work was to optimize the efficiency of pyrosequencing. To do this, 31 SNPs within the hypervariable regions I and II of the D‐loop of human mtDNA were simultaneously analyzed. As a novel approach, we applied two sets of amplification primers for the multiplexing assay. These went in combination with four sequencing primers for pyrosequencing. This method was compared with conventional sequencing of mtDNA from blood and biological trace materials.     

A novel high-resolution chipCE assay for rapid detection of EGFR gene mutations and amplifications in lung cancer therapy by a combination of fragment analysis, denaturing CE and MLPA

There is a growing interest in evaluating molecular markers as predictors of response to new generation of targeted cancer therapies. One of such areas is biological therapy targeting epidermal growth factor receptor gene (EGFR) in lung cancer. The testing of tumor tissue is focused on specific EGFR mutations and EGFR gene amplification, since tumors exhibiting positivity of either of the two marker types are highly sensitive towards the treatment. Although traditional methods of DNA sequencing and fluorescence in situ hybridization are still in use for the detection of EGFR mutations and gene amplification, respectively, there is a need for new dedicated techniques with the primary emphasis on simplicity, sensitivity, speed and cost effectiveness. The main purpose of this work was to integrate diverse assays for both EGFR tests onto a single platform to eliminate the need for different instruments and separate processing. We demonstrate a chip capillary electrophoresis (chipCE) application for EGFR mutation detection by a combination of fragment analysis and denaturing CE along with multiplex ligation-dependent probe amplification (MLPA) for evaluation of EGFR amplification. All separations are carried out in denaturing sieving polymer on a modified Bioanalyzer 2100 chipCE instrument running at temperatures of up to 65°C. The main strength of the resulting high-resolution chipCE application is in its simplicity, speed of analysis and minimal amount of sample required for complete testing of EGFR status. Such an approach could potentially fit medium throughput laboratories providing molecular pathology services for clinical oncologists with fast turnaround times and limited consumption of tissue material.     

A multiplex assay with 52 single nucleotide polymorphisms for human identification

A total of 52 SNPs reported to be polymorphic in European, Asian and African populations were selected. Of these, 42 were from the distal regions of each autosome (except chromosome 19). Nearly all selected SNPs were located at least 100 kb distant from known genes and commonly used STRs. We established a highly sensitive and reproducible SNP-typing method with amplification of all 52 DNA fragments in one PCR reaction followed by detection of the SNPs with two single base extension reactions analysed using CE. The amplicons ranged from 59 to 115 bp in length. Complete SNP profiles were obtained from 500 pg DNA. The 52 loci were efficiently amplified from degraded samples where previously only partial STR profiles had been obtained. A total of 700 individuals from Denmark, Greenland, Somalia, Turkey, China, Germany, Taiwan, Thailand and Japan were typed, and the allele frequencies estimated. All 52 SNPs were polymorphic in the three major population groups. The mean match probability was at least 5.0 x 10(-19) in the populations studied. Typical paternity indices ranged from 336 000 in Asians to 549 000 in Europeans. Details of the 52 SNP loci and population data generated in this work are freely available at http://www.snpforid.org.     

电感耦合等离子体质谱用于多组分免疫分析研究进展

免疫分析在临床医学检测领域具有重要的地位.本课题组提出了基于电感耦合等离子体质谱(ICP-MS)的免疫分析方法,利用元素标记技术结合ICP-MS检测实现多组分免疫分析.随后,研究人员在该领域做了大量研究工作,证明该方法可用于从小分子、蛋白质、核酸到细胞等一系列生物样品的检测.本文综述了基于ICP-MS免疫分析方法的特点,对其发展方向进行了展望,希望为该领域的研究工作提供参考.     

High-throughput droplet analysis and multiplex DNA detection in the microfluidic platform equipped with a robust sample-introduction technique

In this work, a simple, flexible and low-cost sample-introduction technique was developed and integrated with droplet platform. The sample-introduction strategy was realized based on connecting the components of positive pressure input device, sample container and microfluidic chip through the tygon tubing with homemade polydimethylsiloxane (PDMS) adaptor, so the sample was delivered into the microchip from the sample container under the driving of positive pressure. This sample-introduction technique is so robust and compatible that could be integrated with T-junction, flow-focus or valve-assisted droplet microchips. By choosing the PDMS adaptor with proper dimension, the microchip could be flexibly equipped with various types of familiar sample containers, makes the sampling more straightforward without trivial sample transfer or loading. And the convenient sample changing was easily achieved by positioning the adaptor from one sample container to another. Benefiting from the proposed technique, the time-dependent concentration gradient was generated and applied for quantum dot (QD)-based fluorescence barcoding within droplet chip. High-throughput droplet screening was preliminarily demonstrated through the investigation of the quenching efficiency of ruthenium complex to the fluorescence of QD. More importantly, multiplex DNA assay was successfully carried out in the integrated system, which shows the practicability and potentials in high-throughput biosensing.     

Multiplex agarose gel electrophoresis system for variable number of tandem repeats genotyping: Analysis example using Mycobacterium tuberculosis

As one genotyping method for Mycobacterium tuberculosis, variable number of tandem repeats (VNTR) is a promising tool to trace the undefined transmission of tuberculosis, but it often requires large equipment such as a genetic analyzer for DNA fragment analysis or CE system to conduct systematic analyses. For convenient genotyping at low cost in laboratories, we designed a multiplex PCR system that is applicable to agarose gel electrophoresis using fluorescent PCR primers. For tuberculosis genotyping by VNTR, the copy quantities of minisatellite DNA must be determined in more than 12 loci. The system can halve laborious electrophoresis processes by presenting an image of two VNTR amplicons on a single lane. No expensive equipment is necessary for this method. Therefore, it is useful even in developing countries.     

X chromosomal recombination—A family study analyzing 26 X‐STR Loci in Chinese Han three‐generation pedigrees

The aim of this study is to investigate genetic linkage and recombination fractions of 26 X chromosomal (X‐STR) loci with two multiplex PCR systems (MX15‐STR and MX12‐STR). MX15‐STR (including DXS7133, DXS6801, DXS981, DXS6809, DXS7424, DXS6789, DXS9898, DXS7132, GATA165B12, DXS101, DXS10075, DXS6800, GATA31E08, DXS10074, and DXS10079) and MX12‐STR (including DXS6854, DXS9902, DXS6800, GATA172D05, DXS7423, HPRTB, DXS6807, DXS6803, DXS6804, DXS6799, DXS8378, and DXS8377) were successful analyzed on 206 two‐generation families with two or more children and 33 three‐generation families with 72 grandsons. Segregation analysis and calculation of recombination fractions between pairs of markers were performed. Linkage analysis of pairs of markers showed that there existed significant linkage (maximum LOD scores >2.0) within the physical distance of 48.5 Mb. Recombination events could be observed within the clusters of closed linked makers spanning <1.0 Mb. These results indicate that close cluster X‐STRs used and recombination fractions of the selected loci will be very useful for biostatistical calculations in complex kinship analysis.     

Strategy for high-fidelity multiplex DNA copy number assay system using capillary electrophoresis devices

Structural variation of human genome such as duplications and deletions, collectively termed copy number variation (CNV), is one of the major genetic variations. Reliable and efficient measurement of CNV will be essential to develop diagnostic tools for CNV-related diseases. We established a strategy based on multiplex PCR and capillary electrophoresis (CE) for reliable CNV assay. Multiplex-PCR was performed using five primer sets for target loci and a diploid control (DC). We designed primers satisfying three conditions: different size of each PCR product for CE separation, unified annealing temperature for multiplex PCR, and suitability for quantitative PCR (qPCR). We defined the accurate PCR cycles for quantification of copy numbers at which the amplifications for all targets were supposed to be exponential, named maximum doubling cycle. CE was carried out with PCR product and the ratio of the peak areas (target/diploid control) was calculated. Our multiplex PCR-CE analysis reliably determined copy numbers of X chromosome with variable copies ranging from 1 to 5 and showed higher reliability than qPCR (correlation coefficient 0.996 versus 0.898). When measuring the six randomly selected autosomal CNV targets using our multiplex PCR-CE, the results agreed with those from qPCR. In addition, our strategy was validated for the broad application to commonly used CE devices. Taken together, this assay will be useful for accurate analysis of multiple disease-associated CNVs in a clinical setting.