Rapid Prenatal Diagnosis of Down Syndrome Using Quantitative Fluorescent PCR in Uncultured Amniocytes

Rapid prenatal diagnosis of common chromosome aneuploidies have been successful through quantitative fluoresent PCR (QF-PCR) assays and small tandem repeat (STR) markers. The purpose of our study was to investigate the clinical feasibility for rapid prenatal detection of Down syndrome using the quantitative fluorescent PCR in uncultured amniocytes. DNA was extracted from uncultured amniotic fluid of normal karyotype (n=200) and of Down syndrome (n=21). It was amplified using QF-PCR with four STR markers located on chromosome 21. Among normal samples, the ranges of diallelic peaks for at least one STR marker were 1.0-1.3 for D21S11, 1.0-1.4 for D21S1411 and 1.0-1.5 for D21S1270. Down syndrome samples showed trisomic triallelic patterns or trisomic diallelic patterns. The sensitivity, specificity, and efficiency of the assay for detecting Down syndrome were 95.4%, 100%, and 99.5%, respectively. Rapid prenatal diagnosis of Down syndrome using QF-PCR is a reliable technique that aids clinical management of pregnancy

Smart Valving AAO Membrane for Independent On-Off System

2

Nanoporous membranes based on hard and soft templates for biomedical applications

11Nsci

Gold Nanorod Density-Dependent Label-Free Bacteria Sensing on a Flake-like 3D Graphene-Based Device by SERS

Surface-enhanced Raman spectroscopy (SERS) is an effective technique for biosensing, enabling label-free detection of biomolecules with enhanced sensitivity. There is a tremendous probability of signal failure in Raman frequencies because of the scattering of the Raman radiation in liquids, effective SERS improvement is required to reduce this issue when considering liquid specimens. We examined a liquid bacterial sample, investigating the electrostatic interactions of the bacterial samples with gold nanorods (AuNRs) and graphene. We established a voltage-gated 3D graphene functionalized with an AuNR-based device on the silicon substrate for SERS measurements when the applied voltage ranges from 0 to 3 V. Moreover, AuNRs density-susceptible bacterial sample analysis with varied concentrations of bacterial samples has also been described. Using bacterial SERS analysis, the bacterial components amide II (1555–1565 cm−1) and amide III (1250–1350 cm−1) have been discovered for both bacteria, Gram-positive, Listeria monocytogenes and Gram-negative, Salmonella typhi. Our fabricated device affords an interesting label-free, rapid, and reproducible bacterial sample analysis based on the density of the AuNRs when functionalizing flake-like 3D graphene, which can help facilitate label-free bacteria sensing platforms

Hierarchically Self-Organized Monolithic Nanoporous Membrane for Excellent Virus Enrichment

Enrichment of viruses is essential for making high dose viral stocks for vaccines and virus-related research. Since the widely used ultracentrifugation for concentrating viral stock requires ultra-high speed rotation, it easily destroys the activity of some viruses, for instance, hepatitis c virus (HCV), which has a fragile structure and low virus titer. We introduce a novel method to concentrate HCV virus in stock by using a hierarchically self-organized monolithic nanoporous membrane made by stepwise anodization. The pores at the top part of the membrane have very regular sizes that are suitable for the perfect filtration of the virus particles in the stock. On the other hand, the remaining part has large pores that maintain high flux and mechanical strength of the membrane under the high pressure (up to 10 bar). The enrichment efficiency of HCV in crude stocks by using the membrane became over 91%, which is four times higher than that (∼22%) obtained by conventionally used centrifugation. A very high efficiency results from the perfect filtration and no damage to the virion particles during the enrichment process, whereas significant damage to the HCV occurs during centrifugation. The hierarchically self-organized monolithic nanoporous membrane could be effectively employed for concentrating various fragile viruses in stocks, for instance, rabies virus and human immunodeficiency virus in addition to HCV virus

Bioinspired Dual Stimuli-Responsive Membranous System with Multiple On–Off Gates

Stimuli-responsive polymers have been widely used for controlled release of several biomolecules. In general, a single stimulus among various stimuli, for instance, temperature, pH, or light, has been used for these polymers. Although some stimuli are applied together, one cannot control each stimulus independently at a given stimulus-responsive polymer. However, to mimic biological system like cell membrane, multiple on–off gates utilizing independent control of dual (or multiple) stimuli should be used. Here, we introduce a stimuli-responsive membrane controlled by two orthogonal stimuli. For this purpose, the top and the bottom parts of anodized aluminum oxide membrane walls are independently grafted by thermoresponsive poly­(<i>N</i>-isopropylacrylamide) and pH-responsive poly­(acrylic acid), respectively, by using surface-initiated atom transfer radical polymerization. The membrane clearly showed two independent on–off gates depending on temperature and pH. Furthermore, through light irradiation of two different wavelengths (near-infrared and ultraviolet), temperature and pH were also controlled independently and promptly. Thus, this membrane shows two independent on–off gating of the transport of a model biomolecule of fluorescein isothiocyanate-labeled bovine serum albumin. This strategy suggests the potential of independently modified membrane in layers as stimuli-responsive on–off gates for the application of artificial cell membrane