Determination of Zn, Cu and Fe in human patients' serum using micro-sampling ICP-MS and sample dilution.

A high-throughput, sensitive and rapid method was developed for the determination of Zn, Cu and Fe in small volumes (30 μL) of human serum using inductively coupled plasma mass spectrometry (ICP-MS). The sample preparation procedure employed simple 100-fold dilution of the serum samples with 1.0% butanol, 0.

Tricine-SDS-PAGE.

Tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis (tricine-SDS-PAGE) is an efficient way of separating low molecular mass proteins. However, the standard system is quite complicated and specifically may not be useful when the separated proteins are to be recovered from the gel for quantitative analysis. Here, we describe a simplified system whereby these smaller proteins can be resolved in comparatively low percentage gels which have high compatibility with modern detectors such as UV and inductively coupled plasma-mass spectrometry (ICP-MS).

High-Speed, Integrated Ablation Cell and Dual Concentric Injector Plasma Torch for Laser Ablation-Inductively Coupled Plasma Mass Spectrometry.

In recent years, laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS) has gained increasing importance for biological analysis, where ultratrace imaging at micrometer resolution is required. However, while undoubtedly a valuable research tool, the washout times and sensitivity of current technology have restricted its routine and clinical application. Long periods between sampling points are required to maintain adequate spatial resolution.

A feasibility study of the use of saliva as an alternative to leukocytes as a source of DNA for the study of Pt-DNA adducts in cancer patients receiving platinum-based chemotherapy.

This note presents a comparison of the use of saliva versus leukocytes for the determination of Pt-DNA adducts obtained from patients undergoing platinum-based chemotherapy. Samples of both blood and saliva were taken pre- and post-treatment and were analysed via sector-field inductively coupled plasma mass spectrometry (SF-ICP-MS) to determine the level of Pt-DNA adducts formed. As expected, significant inter-patient variability was seen; however, a lack of correlation between the levels of adducts observed in saliva and blood samples was also observed (Pearson correlation coefficient r = -0.

Quantitative analysis of gold nanoparticles in single cells by laser ablation inductively coupled plasma-mass spectrometry.

Single cell analysis has become an important field of research in recent years reflecting the heterogeneity of cellular responses in biological systems. Here, we demonstrate a new method, based on laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS), which can quantify in situ gold nanoparticles (Au NPs) in single cells. Dried residues of picoliter droplets ejected by a commercial inkjet printer were used to simulate matrix-matched calibration standards.

Laser ablation-inductively coupled plasma mass spectrometry: an emerging technology for detecting rare cells in tissue sections.

Administering immunoregulatory cells to patients as medicinal agents is a potentially revolutionary approach to the treatment of immunologically mediated diseases. Presently, there are no satisfactory, clinically applicable methods of tracking human cells in patients with adequate spatial resolution and target cell specificity over a sufficient period of time. Laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) represents a potential solution to the problem of detecting very rare cells in tissues.

Single cell tracking of gadolinium labeled CD4+ T cells by laser ablation inductively coupled plasma mass spectrometry.

Cellular therapy is emerging as a promising alternative to conventional immunosuppression in the fields of hematopoietic stem cell (HSC) transplantation, autoimmune disease, and solid organ transplantation. Determining the persistence of cell-based therapies in vivo is crucial to understanding their regulatory function and requires the combination of an extremely sensitive detection technique and a stable, long-lifetime cell labeling agent. This paper reports the first application of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to perform single cell detection of T cell populations relevant to cellular immunotherapy.

Oxaliplatin complexes with carnosine and its derivatives: in vitro cytotoxicity, mass spectrometric and computational studies with a focus on complex fragmentation.

The complexation of the Pt-based anti-cancer drug oxaliplatin (OxPt) with biological ligands other than DNA is believed to be a major cellular sink for the drug reducing its therapeutic potential and acting as a potential cause of toxicity. In this paper, the very first hypothesis driven investigation of the role of the naturally abundant cytoplasmic dipeptide ligand β-alanyl-l-histidine dipeptide (carnosine) in OxPt detoxification is presented. In vitro studies on hepatocellular carcinoma HepG2 cells suggest that carnosine may inhibit the cytotoxic action of OxPt most likely through the formation of complexes that are less cytotoxic than OxPt alone.

Interactions of oxaliplatin with the cytoplasmic thiol containing ligand glutathione.

The complexation of the Pt-based anti-cancer drug oxaliplatin (OxPt) with biological ligands other than DNA is believed to be a major cellular sink for the drug reducing its therapeutic effect and acting as a potential cause of toxicity. In this paper, linear ion trap electrospray ionization mass spectrometry was employed to study the interaction of oxaliplatin with the cytoplasmic thiol containing tripeptide ligand γ-l-glutamyl-l-cysteinyl-glycine (GSH) this being the most abundant low-molecular-weight thiol containing molecule in human cells. Evidence of protonated dimers and multimers of oxaliplatin, protonated multimers of glutathione as well as several different combinations of these protonated species is presented.

Tricine-SDS-PAGE.

Tricine-sodium dodecyl sulphate-polyacrylamide gel electrophoresis (tricine-SDS-PAGE) is an efficient way of separating low-molecular-mass proteins. However, the standard system is quite complicated and specifically may not be useful when the separated proteins require to be recovered from the gel for quantitative analysis. Here, we describe a simplified system whereby these smaller proteins can be resolved in comparatively low-percentage gels which have high compatibility with modern detectors such as UV and inductively coupled plasma mass spectrometry (ICP-MS).

Liquid chromatography-flame ionisation detection using a nebuliser/spray chamber interface. Part 2. Comparison of functional group responses.

The application of a LC-nebuliser/spray chamber interface-flame ionisation detection has been demonstrated for the superheated water liquid chromatography of a wide range of aliphatic and aromatic analytes. The linearity and sensitivity of the response of volatile and involatile analytes have been compared. The response of the detector toward different analytes is similar to that in GC-FID and for volatile analytes was comparable to UV detection.

Liquid chromatography-flame ionisation detection using a nebuliser/spray chamber interface. Part 1. Design and testing.

A nebuliser and spray chamber have been used to link a flow injection analyser to a flame ionisation detector, with the potential for the combination to be used as a universal detector for liquid chromatography. The hydrogen and air flows were adjusted to achieve a stable system. The detector responded to both volatile and involatile analytes and to compounds with and without chromophores, including alkanes, alkanols, aromatic amides and acids, phenols, amino-acids and carbohydrates and gave a linear response for many analytes.

Analysis of mono-phosphate nucleotides as a potential method for quantification of DNA using high performance liquid chromatography-inductively coupled plasma-mass spectrometry.

The determination of total deoxyribonucleic acid (DNA) concentration is of great importance in many biological and bio-medical analyses. The quantification of DNA is traditionally performed by UV spectroscopy; however the results can be affected greatly by the sample matrix. The proposed method quantifies phosphorus in digested calf thymus DNA and human DNA by high performance liquid chromatography (HPLC) combined with inductively coupled plasma mass spectrometry (ICP-MS).

Speciation of oxaliplatin adducts with DNA nucleotides.

This paper describes a set of fast and selective high performance liquid chromatography (HPLC) methods coupled to electro-spray ionisation linear ion trap mass spectrometry (ESI-MS), sector-field inductively coupled plasma mass spectrometry (SF-ICP-MS) and UV detection for in vitro studies of the bifunctional adducts of oxaliplatin with mono-nucleotides, di-nucleotides and cellular DNA. The stationary phases and the optimised conditions used for each separation are discussed. Interaction of oxaliplatin with A and G mono-nucleotides resulted in the formation of five bifunctional platinum diaminocyclohexane (DACHPt) adducts.

A comparison of Tris-glycine and Tris-tricine buffers for the electrophoretic separation of major serum proteins.

This paper compares different buffer systems for the electrophoretic separation of the five most abundant serum proteins on native-PAGE gel and cellulose membranes. A modified Tris-tricine system was shown to be superior for the separation of these serum proteins in a 7% m/v native-PAGE gel as compared with the traditionally used Tris-glycine and Tris-tricine methods. This modified Tris-tricine buffer system was also employed for the separation of serum proteins using a cellulose acetate membrane and very effective separation was observed as compared with the traditionally used Tris-barbital and Tris-glycine buffer systems.

Modification of tricine-SDS-PAGE for online and offline analysis of phosphoproteins by ICP-MS.

This study describes a modification to tricine sodium dodecyl sulphate polyacrylamide gel electrophoresis to make it more effective for the separation of low molecular mass proteins and for coupling with inductively coupled plasma mass spectrometry (ICP-MS). The modified method employs low-percentage polyacrylamide gels (7-10%) (w/v) and low reagent concentrations that provide efficient separations, good quantitation and low matrix levels that are compatible with ICP-MS. Using phosphopeptides as a model system, and offline analysis, we obtained recoveries of 73% (w/v) in a 9% gel compared with 55% in a conventional 16% gel.

A study of oxaliplatin-nucleobase interactions using ion trap electrospray mass spectrometry.

Oxaliplatin is an important anti-cancer drug that has been approved for the treatment of colorectal cancer. It is known that oxaliplatin, like other Pt-based drugs, interacts with DNA to form cytotoxic Pt-DNA adducts that disrupt important biological processes such as DNA replication and protein synthesis. Linear ion trap electrospray ionisation mass spectrometry (ESI-MS) was employed to study the interaction of oxaliplatin with DNA nucleobases.

Determination of iodine and molybdenum in milk by quadrupole ICP-MS.

A reliable method for the determination of iodine and molybdenum in milk samples, using alkaline digestion with tetramethylammonium hydroxide and hydrogen peroxide, followed by quadrupole ICP-MS analysis, has been developed and tested using certified reference materials. The use of He+O2 (1.0 ml min(-1) and 0.

Silver nanoparticles and polymeric medical devices: a new approach to prevention of infection?

Objectives: Implantable devices are major risk factors for hospital-acquired infection. Biomaterials coated with silver oxide or silver alloy have all been used in attempts to reduce infection, in most cases with controversial or disappointing clinical results. We have developed a completely new approach using supercritical carbon dioxide to impregnate silicone with nanoparticulate silver metal.