Biological, Medical, and Clinical Analysis

A total of fourteen cuts were defined because the retention time difference between several skin sensitizors was only slight.

This month's installment of "Column Watch" is the first of a two-part series in which columnist Ron Majors examines the trends and highlights in columns and consumables at Pittcon 2008.

In the last year, two new protein depletion products have been introduced, and these will be the focus of this month's installment of "Directions in Discovery."

This article aims to demonstrate the unique capability of resin-based mixed-mode solid-phase extraction (SPE) to achieve efficient extraction of basic drugs from plasma. Optimized pore size of the method minimizes retention of high molecular weight matrix components present in the biological fluid samples. The interferences are removed, ensuring extremely clean extracts for subsequent liquid chromatography?mass spectrometry-mass spectrometry (LC-MS-MS) analysis.

This article describes the method development and performance characteristics of the validated LFI assay and evaluates stability in human plasma.

Selective sample preparation techniques are particularly attractive for the analysis of trace amounts of small molecules in complex matrices. In this month's instalment, columnist Ron Majors covers the field of immunoextraction, a technique that employs immobilized antibodies to selectively capture specific analytes using molecular recognition via antibody–antigen interactions. Recently, the introduction of commercial products for specific high-volume environmental and food safety applications should spur further applications of this technique.

The 59th Annual Pittsburgh Conference and Exposition on Analytical Chemistry and Applied Spectroscopy (Pittcon 2008) will be held at the Ernest N. Morial Convention Center, New Orleans, Louisiana, USA, from 2–6 March, 2008. Pittcon 2008's Technical Program will be in the format of invited symposia, organized contributed oral sessions, contributed oral sessions, workshops, new product forums and poster sessions to cover the latest developments in the traditional and emerging disciplines of analytical chemistry and applied spectroscopy. Following on from last year's success, the networking sessions will be expanded.

BMC Pediatrics reports on a study characterizing total homocysteine (tHcy) levels at birth in preterm and term infants and identifing associations with intraventricular hemorrhage (IVH) and other neonatal outcomes such as mortality, sepsis, necrotizing enterocolitis, bronchopulmonary dysplasia, and thrombocytopenia.

In this month?s installment, columnist Ron Majors covers the field of immunoextraction, a technique that employs immobilized antibodies to selectively capture specific analytes using molecular recognition via antibody?antigen interactions. Recently, the introduction of commercial products for specific high-volume environmental and food safety applications has spurred further applications of this technique.

Polymer-based columns still are widely used in size-exclusion chromatography (SEC) and ion chromatography-ion-exchange chromatography - they have always been used in these modes, even back in 1987.

Assay Depot, an Internet marketplace for drug discovery services, today announced that Nanostream, provider of chromatography products and services to increase productivity in analytical laboratories at pharmaceutical and biotech companies, will join the company?s service provider network.

HPLC 2007 was held in Ghent, Belgium in June. Last month, columnist Ron Majors summarized some the important column developments as well as other Symposium highlights. This month, he winds up coverage with additional highlights in the areas of technology and applications. Among the topics covered are stationary phase preparation and characterization, multi-dimensional and comprehensive LC, temperature studies, detectors and an application overview.

Leipziger Messe, organisers of L.A.B. - the trade fair and conference devoted to analysis, bio and laboratory equipment - have announced that the show will host 88 exhibitors from countries including the UK, US, France, Italy, Finland, the Netherlands, and Germany. L.A.B. takes place from 2-4 October 2007 at ExCeL London.

Waters Corporation (Milford, Massachusetts) and Lambda Therapeutic Research Ltd (Mumbai, India) recently announced a joint cooperative agreement that provides innovative analytical laboratory equipment designed to enhance research quality service and business solutions for Lambda and its clients.

Science Daily, a website that features news revolving around the sciences, has published an article that describes new chromatographic techniques for the analysis of pesticides and antibiotics in food and beverage samples.

Nanostream, provider of products and services that increase productivity in laboratories at pharmaceutical and biotech companies, extends its global reach to Europe by establishing a sales and support office in The Netherlands.

Reuters Health has published an article that describes how Dr. Ping Wang of Zhejiang University, Hangzhou, and his colleagues used solid-phase microextraction combined with gas chromatography (GC) to analyze exhaled volatile organic compound (VOC) markers to help with the diagnosis of lung cancer.

The Victoria Advocate (Victoria, TX) published an article about the random testing of high school student-athletes in the Texas public school system. The article is entitled "No Steroid Test is Foolproof" and focuses on the process of drug testing using gas chromatography-mass spectroscopy (GC-MS).

This month's Market Profile looks at single-cell PCR, an application of PCR technology, which deals with the nucleic acid in single cells rather than in a tissue sample or a pool of homogenous cells.

The evaluation of the state of a biological sample before starting the complex analyses is a crucial step in proteomics studies. This paper compares planar polyacrylamide gel electrophoresis (SDS-PAGE) and capillary on-the-chip SDS GE (CGE-on-the-chip) in terms of the speed of analysis, sensitivity and flexibility. Snake venoms, which are heterogeneous with high bioactivity and consist mainly of proteins with a molecular weight mass range below 100 kDa, were investigated. CGE-on-the-chip was found to be a faster and more stable technique, providing more information than classical SDS-PAGE. CGE-on-the-chip was also capable of detecting many compounds over a broad molecular weight mass range whereas the SDS-PAGE is more time-consuming and provides acceptable resolution either in the very low (below 17 kDa) or in the mid- to high-molecular mass region (16–200 kDa) depending on the gel/buffer-system selected.

Single-cell PCR is an application of PCR technology, which deals with the nucleic acid in single cells rather than in a tissue sample or a pool of homogenous cells. While single-cell amplification has been recognized almost as long as the PCR technology itself, it was not considered a very efficient technique due to uncontrollable circumstances such as the lack of available primers and efficient cell-lysing techniques, which only allowed a small quantity of cell DNA to be amplified.

Thermo Fisher Scientific has announced that its informatics solutions have won Scientific Computing's 2007 Readers' Choice Awards in four categories.

Molecularly imprinted polymers (MIPs) are synthetic polymeric materials that mimic immunosorbents. They are widely used as sorbents for solid-phase extraction (SPE). The most common way to synthesize them is bulk polymerization because of its simplicity and versatility. This produces a hard monolith that has to be ground and sieved to obtain particles in the desired size range. However, the partial loss of the materials as fine dusts; the irregular shape of the particles produced and their wide size distribution, have led to a search for different polymerization methods to offset the drawbacks of the bulk polymerization process.

LC–MS–MS methods for the unambiguous identification and quantification of pesticides in complex matrix samples are well known and widely used. Triple quadrupole systems have proven useful for this task because of their high specificity in MS–MS mode and their low detection limits. However, working in targetted MS–MS mode prevents the detection of other compounds.

Analysis by mass spectrometry (MS) of integral membrane proteins and those associated with membrane is an important aspect of proteomics.

Peptide mapping is one of the preferred techniques for the comprehensive characterization of biopharmaceutical products and is often the analytical method of choice for studying a protein's primary structure.

The complexity of the systems that are used vary from standard GC configurations to assess the effectiveness of protective clothing to trace analysis of biomedical samples with complex GC configuration.

This installment of "Sample Prep Perspectives" discusses techniques for the reduction/depletion of high-abundance proteins.

The concept of membrane-controlled processes is widespread in nature. Nearly all biological mechanisms concerning mass transport and exchange are regulated by membrane barriers and a variety of technical and biotechnological applications have been devised based on this mechanism. Membrane applications in analytical chemistry are geared towards the enrichment of target substances from an aqueous solution or the separation of compounds from a complex matrix. This article describes membrane-assisted extraction processes to separate traces of polar pharmaceutical substances the so called emerging micropollutants from aqueous samples. Basic prospects and examples of membrane-supported extractions are presented.