Integrated microfluidic bioprocessor for single-cell gene expression analysis

An integrated microdevice is developed for the analysis of gene expression in single cells. The system captures a single cell, transcribes and amplifies the mRNA, and quantitatively analyzes the products of interest. The key components of the microdevice include integrated nanoliter metering pumps, a 200-nL RT-PCR reactor with a single-cell capture pad, and an affinity capture matrix for the purification and concentration of products that is coupled to a microfabricated capillary electrophoresis separation channel for product analysis. Efficient microchip integration of these processes enables the sensitive and quantitative examination of gene expression variation at the single-cell level. This microdevice is used to measure siRNA knockdown of the GAPDH gene in individual Jurkat cells. Single-cell measurements suggests the presence of 2 distinct populations of cells with moderate (≈50%) or complete (≈0%) silencing. This stochastic variation in gene expression and silencing within single cells is masked by conventional bulk measurements

Identification and characterization of textile fibers by thermal analysis

Textile fibers are ubiquitous in the sense that they are present in the fabric of clothing, furniture, floor and wall covering. A remarkable variety of textile fibers with different chemical compositions are produced for many different commercial applications. As fibers are readily transferred they are frequently recovered from crime scenes as trace evidence and may provide useful forensic information for identification purposes. The objective of the experiment described in this paper is to evaluate specific thermal analysis techniques (DSC and TGA) as means by which textile fibers or cloth fragments may be reliably identified using experimentally simple and reproducible instrumental methods. The results are analyzed to determine whether these techniques may serve to identify different textiles on the basis of their thermal behavior, to decide if sample matching is possible and to evaluate detection limits for the sample-instrument combination used.Fundação para a Ciência e a Tecnologia (FCT

Quantitative measurement of collagen methylation by capillary electrophoresis

10.1002/elps.200406071Electrophoresis25203416-3421ELCT