Showing papers in "Analytical Biochemistry in 1999"

TL;DR: The phosphomolybdenum method is routinely applied in the laboratory to evaluate the total antioxidant capacity of plant extracts and to determine vitamin E in a variety of grains and seeds, including corn and soybean.

TL;DR: validation of a real-time RT-PCR method to quantitate mRNA expression levels of atrial natriuretic peptide and c-fos in an in vitro model of cardiac hypertrophy and shows that the GAPDH gene chosen for normalization of the RNA load is truly invariant throughout the biological treatments examined.

TL;DR: This application would not be restricted to antigen-antibody systems, protein microarrays should provide a general resource for high-throughput screens of gene expression and receptor-ligand interactions.

TL;DR: TCEP has advantages over DTT, although the choice of reductant is application specific: in electron paramagnetic resonance (EPR) spectroscopy utilizing nitroxide spin labels, TCEP is highly advantageous: spin labels are two to four times more stable in T CEP than D TT, thereby alleviating a long-standing problem in EPR.

TL;DR: A range of hydroperoxides were reduced by ferrous ions in acid solutions and the amount of ferric product was measured as a xylenol orange complex at 560 nm, allowing the determination of approximate hydroperoxide concentrations even in chemically complex systems.

TL;DR: The conjugation of phosphor particles to NeutrAvidin is described with the subsequent use of this conjugate in a model system consisting of prostate-specific antigen in tissue sections and the CD4 membrane antigen on human lymphocytes.

TL;DR: This new unsymmetrical cyanine dye, SYBR Gold nucleic acid gel stain, has two fluorescence excitation maxima when bound to DNA, one centered at approximately 300 nm and one at approximately 495 nm, and is found to be as sensitive as silver staining for detecting DNA-with a single-step staining procedure.

TL;DR: The application of MALDI-TOF-MS for the analysis of diacylglycerols, phosphatidylcholines, and (poly)phosphoinositides is reported here for the first time, and it is shown that in a matrix of 2,5-dihydroxybenzoic acid the molecular ions are easily detected even in complex mixtures, and thus, detailed data on the fatty acid composition are provided.

TL;DR: In this article, the authors modify the original CR-insulin method for quantifying Abeta aggregation and discuss the reasons why application of the original method is not valid for this purpose.

TL;DR: Oligonucleotides attached by this method provided a highly efficient substrate for nucleic acid hybridization and primer extension assays and patterning of multiple DNA probes on a glass surface utilizing this attachment chemistry, which allows for array densities of at least 20,000 spots/cm2.

TL;DR: Mass spectral peak locations were consistent with previously reported post-translational modifications involving N-terminal methionine loss, methylation, thiomethylation, and acetylation for all but one case.

TL;DR: It is shown that the mu, delta, and kappa opioid receptors and the related nociceptin receptor, ORL1, each couple to Galphaqi5, Galphaqo5, and Galpha16 and that different receptor/G protein combinations show different levels of maximal activation.

TL;DR: An improved method for the measurement of F2-isoprostanes using stable isotope dilution capillary gas chromatography/electron capture negative ionization mass spectrometry (GC-ECNI-MS) represents a significant advance in terms of the rapidity and yield in the purification of biological samples.

TL;DR: Several proteins expressed in Escherichia coli with the N-terminus Gly-Ser-Ser-[His]6- consisted partly (up to 20%) of material with 178 Da of excess mass, sometimes accompanied by a smaller fraction with an excess 258 Da, which suggested that the +258-Da modification was addition of a 6-phosphogluconoyl group.

TL;DR: A glucose sensor based on a mutant glucose/galactose binding protein (GGBP) and phase-modulation fluorometry and results suggest an approach to glucose sensing with simple devices are suggested.

TL;DR: A series of disaccharide composition of tetra- and hexasaccharides derived from chondroitin sulfate and heparin/heparan sulfate were derivatized at their reducing ends with a fluorophore 2-aminobenzamide to develop a sensitive microanalytical method for glycosaminoglycans.

TL;DR: For the first time oscillations of intracellular metabolite concentrations like glucose-6-phosphate, phosphoenolpyruvate, glyceraldehyde 3-ph phosphate, dihydroxyacetonphosphates, 3-Phosphoglycerate, and pyruvates were quantified on a subseconds to seconds scale in E. coli.

TL;DR: Quantitative measurements on microplates indicate that DDI proceeds with a higher immobilization efficiency than conventional immobilization techniques, such as the binding of the biotinylated proteins to streptavidin-coated surfaces or direct physisorption, and simultaneous immobilization of different compounds using microstructured oligonucleotide arrays as immobilization matrices demonstrate that D DI proceeds with site selectivity due to the unique specificity of Watson-Crick base pairing.

TL;DR: It is demonstrated that the inner filter effect correction of microtiter plate reader velocities enables rapid measurement of Ki and Ki' values and kinetic inhibition mechanisms for HCV NS3 protease inhibitors.

TL;DR: This prototype assay demonstrates the usefulness of the microchips for performing enzymatic assays for which fluorogenic substrates cannot easily be designed.

TL;DR: A rapid enzymatic method to quantify mass levels of sphingosine 1-phosphate (SPP) in serum, mammalian tissues, and cultured cells was described in this paper.

TL;DR: The purpald assay is superior to the Kdo assay because: (i) No acid hydrolysis of the samples and no boiling in the assay process are required; thus, it can be directly carried out with microtiter plates for a large number of samples at room temperature.

TL;DR: The measurements of F2-isoprostanes by EIA and GCMS are not equivalent and comparison of levels derived using a GCMS method which estimates concentration from a peak encompassing a number of F-ISoprostane isomers, and levels derived from enzyme immunoassay measuring a specific isoprostan, may be inappropriate.

TL;DR: An immunochemical technique for the quantification of carbonyl groups in protein samples prepared from small tissue samples and cell cultures was developed and results were highly correlated with those of the standard DNPH-based spectrophotometric technique.

TL;DR: In an initial screening of five phosphatase substrates based on fluorinated derivatives of 4-MU, it was found that one substrate, 6,8-difluoro-4-methylumbelliferyl phosphate (DiFMUP), was much improved for the detection of acid phosphat enzyme activity.

TL;DR: Five colorimetric methods of phosphate analyses based on formation of a phosphomolybdate complex and compatible with the automated assay were tested, and the fundamental chemistry is discussed, where color stability and low blanks are more important than sensitivity.

TL;DR: The metabolic products of daidzein and genistein, the principal isoflavones of soy, were examined and some corrections were made concerning the earlier published data of dihydrogenistein and 6'-OH-O-dma.

TL;DR: It is established that NTA is the optimal ligand to chelate the different forms of NTBI present in sera and can be adopted for utilization in the NTBI assay.

TL;DR: A rapid and continuous spectrophotometric activity assay for cytochrome P450 BM-3 based on the conversion of p-nitrophenoxycarboxylic acids (pNCA) to omega-oxycaroxydodecanoic and the chromophore p-Nitrophenolate was developed.