Miniaturized PCR systems for cancer diagnosis

Simultaneous detection of MCF-7 and HepG2 cells in blood by ICP-MS with gold nanoparticles and quantum dots as elemental tags

In this work, we demonstrate a novel method based on inductively coupled plasma mass spectrometry (ICP-MS) detection with gold nanoparticles (Au NPs) and quantum dots (QDs) labeling for the simultaneous counting of two circulating tumor cell lines (MCF-7 and HepG2 cells) in human blood. MCF-7 and HepG2 cells were captured by magnetic beads coupled with anti-EpCAM and then specifically labeled by CdSe QDs-anti-ASGPR and Au NPs-anti-MUC1, respectively, which were used as signal probes for ICP-MS measurement. Under the optimal experimental conditions, the limits of detection of 50 MCF-7, 89 HepG2 cells and the linear ranges of 200-40000 MCF-7, 300-30000 HepG2 cells were obtained, and the relative standard deviations for seven replicate detections of 800 MCF-7 and HepG2 cells were 4.6% and 5.7%, respectively. This method has the advantages of high sensitivity, low sample consumption, wide linear range and can be extended to the simultaneous detection of multiple CTC lines in human peripheral blood.

Fluorescent-magnetic-biotargeting multifunctional nanobioprobes for detecting and isolating multiple types of tumor cells

Fluorescent-magnetic-biotargeting multifunctional nanobioprobes (FMBMNs) have attracted great attention in recent years due to their increasing, important applications in biomedical research, clinical diagnosis, and biomedicine. We have previously developed such nanobioprobes for the detection and isolation of a single kind of tumor cells. Detection and isolation of multiple tumor markers or tumor cells from complex samples sensitively and with high efficiency is critical for the early diagnosis of tumors, especially malignant tumors or cancers, which will improve clinical diagnosis outcomes and help to select effective treatment approaches. Here, we expanded the application of the monoclonal antibody (mAb)-coupled FMBMNs for multiplexed assays. Multiple types of cancer cells, such as leukemia cells and prostate cancer cells, were detected and collected from mixed samples within 25 min by using a magnet and an ordinary fluorescence microscope. The capture efficiencies of mAb-coupled FMBMNs for the above-mentioned two types of cells were 96% and 97%, respectively. Furthermore, by using the mAb-coupled FMBMNs, specific and sensitive detection and rapid separation of a small number of spiked leukemia cells and prostate cancer cells in a large population of cultured normal cells (about 0.01% were tumor cells) were achieved simply and inexpensively without any sample pretreatment before cell analysis. Therefore, mAb-coupled multicolor FMBMNs may be used for very sensitive detection and rapid isolation of multiple cancer cells in biomedical research and medical diagnostics.

Microfluidics in macro-biomolecules analysis: macro inside in a nano world

Use of microfluidic devices in the life sciences and medicine has created the possibility of performing investigations at the molecular level. Moreover, microfluidic devices are also part of the technological framework that has enabled a new type of scientific information to be revealed, i.e. that based on intensive screening of complete sets of gene and protein sequences. A deeper bioanalytical perspective may provide quantitative and qualitative tools, enabling study of various diseases and, eventually, may offer support for the development of accurate and reliable methods for clinical assessment. This would open the way to molecule-based diagnostics, i.e. establish accurate diagnosis and disease prognosis based on identification and/or quantification of biomacromolecules, for example proteins or nucleic acids. Finally, the development of disposable and portable devices for molecule-based diagnosis would provide the perfect translation of the science behind life-science research into practical applications dedicated to patients and health practitioners. This review provides an analytical perspective of the impact of microfluidics on the detection and characterization of bio-macromolecules involved in pathological processes. The main features of molecule-based diagnostics and the specific requirements for the diagnostic devices are discussed. Further, the techniques currently used for testing bio-macromolecules for potential diagnostic purposes are identified, emphasizing the newest developments. Subsequently, the challenges of this type of application and the status of commercially available devices are highlighted, and future trends are noted.

Pharmacogenetics in heart failure: how it will shape the future

Pharmacogenomics is a growing field of research that focuses on how an individual's genetic background influences his or her response to therapy with a drug or device. Increasing evidence from clinical trials in patients with heart failure (HF) due to systolic dysfunction suggests that genetic variations can predict the occurrence of HF, influence the effects of standard therapies, and influence outcomes of HF patients. This article reviews the underlying principles of pharmacogenomics, discusses some of the complex variables that influence the investigational approach to pharmacogenomics, demonstrates how variations in genes encoding a variety of different proteins can influence the effects of pharmacologic agents, and describes the potential impact of pharmacogenomics on the treatment of patients with HF.

Advances in Nucleic Acid Detection and Quantification

The last decade has seen many changes in molecular biology at the bench, as we have moved away from a primary goal of cataloguing genes and mRNA towards techniques that detect and quantify nucleic acid molecules even within single cells. With the invention of the polymerase chain reaction (PCR), a nucleic acid sequence could now be amplified to generate a large number of identical copies, and this launched a new era in genetic research. PCR has developed in parallel to fluorescent hybridization probing to provide low-, medium- and high-throughput detection methods. However, PCR and hybridization detection have significant drawbacks as long-term solutions for routine research and diagnostics assays. Therefore many novel methods are being developed independently, but as yet no one technique has emerged as a clear replacement for PCR, microarrays or even sequencing. In order to examine the technological horizon in this area, around 90 delegates assembled at Hinxton Hall, Cambridge, U.K. on 28 and 29 October 2008 for a Biochemical Society/Wellcome Trust Focused Meeting sponsored by Thermo Fisher Scientific and the British Library. The title of the meeting was ‘Advances in Nucleic Acid Detection and Quantification’, and the primary aim was to bring together scientists from different disciplines who nevertheless are trying to develop reliable methods for the quantification or detection of RNA and DNA molecules. This meant that physical and organic chemists, microbial ecologists and clinicians appeared alongside molecular biologists. An introductory session on general nucleic acid detection technologies was initiated with a fascinating insight into single-molecule, singlecell hybridization from Professor Sir Edwin Southern. This served as an ideal base for sessions on single-cell molecular biology and an examination of current applications of emerging technology. This issue of Biochemical Society Transactions contains some of the papers prepared by speakers at the meeting, and highlights not only how PCR and microarrays are already being replaced, but also which methods are likely to replace them.