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Expensive Reagents (expensive + reagent)

Distribution by Scientific Domains

Chemistry	50%

Selected Abstracts

Production of hybrid phage displaying secreted aspartyl proteinase epitope of Candida albicans and its application for the diagnosis of disseminated candidiasis

MYCOSES, Issue 3 2007
Qiong Yang
Summary The secreted aspartyl proteinases (Saps) of Candida albicans have been implicated as immunodominant antigens and virulence factors associated with adherence and tissue invasion. A hybrid phage displaying the Sap epitope VKYTS was constructed by cloning the corresponding DNA fragments into the pfd88 vector. Similar to native Sap, the phage-displayed epitope showed reactivity to sera from mice and patients with systemic C. albicans infection but not from those with oropharyngeal candidiasis and healthy individuals on Western blot. Furthermore, a new enzyme-linked immunosorbent assay was developed to detect the anti-Sap antibody with hybrid phage displaying Sap epitope VKYTS that can be recognised by anti-Sap antibodies. Sequential sera were tested from patients and mice with systemic candidiasis and oropharyngeal candidiasis, and serum samples from healthy individuals were also included. The sensitivity and specificity were 77% and 88.3% for experimental mice, respectively. These values reached 60% and 85%, respectively, for human patients. These data indicate this phage-displayed epitope as an effective and less expensive reagent would be a valuable probe for the detection of specific Sap antibody in the sera of patients and mice with systemic C. albicans infection. [source]

Determination of HIV-1 subtypes (A,D, F, G, CRF01_AE) by PCR in the transmembrane region (gp41) with novel primers

JOURNAL OF MEDICAL VIROLOGY, Issue 1 2005
Fumihiro Yagyu
Abstract HIV-1 has a huge genetic diversity. So far, nine subtypes have been isolated, namely, subtypes A, B, C, D, F, G, H, J, and K. Epidemiological study provides information which may help in the development of HIV-1 prevention programs or health policies. In the future, subtyping may also be critical for vaccine development, and an effective anti-viral drug will need to be effective for different subtypes of HIV virus. The analysis of the nucleotide sequence of the v3 region is considered the most reliable method for determining the HIV-1 subtype. However, the procedures for determining the v3 sequences are complicated and time consuming, requiring expensive reagents, equipment, and well-trained personnel. The polymerase chain reaction (PCR) method using subtype-specific primers for HIV-1 subtyping is easier and faster. The objective of this study was to develop subtype-specific primers for subtyping PCR. The specific primers were designed for subtypes A, B, C, D, F, G, and CRF01_AE, and these primers could be applied to assay for various HIV-1 subtypes in the clinical samples. The specific primers were designed for each subtypes in the gp41 region. The result of PCR was compared with the subtypes which was determined by the v3 sequence. The results of subtyping by PCR using the newly designed primers could detect 29 of 33 patients tested, and all matched those obtained by nucleotide sequencing of the env v3 region except for three subjects, which were differentiated as CRF02_AG. The newly designed primers functioned accurately and conclusively. In comparison with PCR as a method for the determination of subtypes, sequence analysis requires better-trained personnel, more expensive reagents, and more equipment and time. J. Med. Virol. 76:16,23, 2005. © 2005 Wiley-Liss, Inc. [source]

In vacuo isotope coded alkylation technique (IVICAT); an N-terminal stable isotopic label for quantitative liquid chromatography/mass spectrometry proteomics,

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 16 2006
Brigitte L. Simons
We present a new isotopic labeling strategy to modify the N-terminal amino group of peptides in a quantifiable reaction without the use of expensive reagents or solvents. The In Vacuo Isotope Coded Alkylation Technique (IVICAT) is a methylation reaction, carried out at low pressure (<100,mTorr), that results in a stable quaternary trimethylammonium group, thus adding a permanent positive charge at the N-terminus of peptides without modifying the , -amino groups of lysine. The methylation reaction increases the signal intensity of modified peptides in matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) and liquid chromatography (LC)/MS and the isotopic peak pair differs by 9 mass units which can be easily resolved by either instrument. N-terminally trimethylated peptides exhibit collision-induced dissociation (CID) mass spectra that differ from their unmodified analogues by an enhanced b -ion series in MS2 spectra due to the fixed positive charge. Using LC/MS/MS with an LTQ mass analyzer for quantification, the experimentally determined ratios of H9 - to D9 -trimethyl-labeled peptides of , -casein provided accurate estimates of the actual ratios with low % error. IVICAT labeling also accurately quantified proteins in rat kidney inner medullary collecting duct cell types, as judged by comparison with relative quantification by subsequent immunoblotting experiments. IVICAT labeling, when used in conjunction with the new proteomics software QUIL, can accurately report relative protein abundances and increase the sequence coverage of proteins of tissue proteomes. Published in 2006 by John Wiley & Sons, Ltd. [source]

Synthetic approaches to 3H -naphtho[2,1- b]pyrans and 2,3-dihydro-1H -naphtho[2,1- b]pyrans

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 6 2009
Amitabh Jha
Naphtho[2,1- b]pyran nuclei are prevalent in natural products with significant biological and medicinal properties. 3,3-Disubstituted 3H -naphtho[2,1 -b]pyrans are photochromic and find use in electronic display systems, ophthalmic lenses, optical switches, and temporary or permanent memories. Of the various possible structural isomers of naphthopyran framework, this review is an account of reported synthetic procedures to produce 3H -naphtho[2,1-b]pyrans and their dihydro analogs, 2,3-dihydro-1H -naphtho[2,1 -b]pyrans. The advantages and disadvantages of each procedure in terms of yields, complexity, formation of side-products, use of uncommon/expensive reagents, etc., are also described. J. Heterocyclic Chem., (2009). [source]