摘要:

Ordinary AT-cut, quartz, piezoelectric crystals as commonly used in watches, radios, computers, etc., were used to detect the hybridization of complementary strands of synthetic RNA's. The method is based on the large absolute mass increase accompanying hybridization. Nucleic acid strands were covalently attached to the polymer-modified surface of a piezoelectric crystal. When these immobilized probe strands were melted and then incubated with complementary target strands in solution, association of probe and target to form duplexes resulted in an increase in the effective mass of the crystal. After washing away indifferently bound material, a mass increase was detectable as a decrease of several hundred Hertz in the crystal's resonance frequency, relative to control crystals on which non-complementary strands were incubated. The encouraging preliminary results suggest that the method may be useful as a non-radioactive means of identifying DNA and RNA. Furthermore, the method requires only very simple equipment, the crystals used are inexpensive, and the results are quantitative as well as qualitative.

ISSN:0003-2719    

DOI:10.1080/00032718808055499

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A PVC matrix nonactin based membrane electrode assembled with a solid carbon-epoxy inner electric contact has been successfully used in ammonium and urea analysis.

ISSN:0003-2719    

DOI:10.1080/00032718808055500

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A new method for spin labeling the lipid bilayer component in erythrocyte membranes at low hematocrit with extremely low concentration of 4-(N,N-dimethyl-l-n-hexadecyl)ammonium-2,2,6,6-tetramethylpiperidine-l-oxyl iodide, (CAT-16) is described. Characterization of the motional determinants of CAT-16 in erythrocyte membranes at 20°C is presented from which it is deduced that protein-lipid interactions in the lipid bilayer arc primary.

ISSN:0003-2719    

DOI:10.1080/00032718808055501

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A novel and ultrasensitive sandwich enzyme immunoassay (sandwich transfer enzyme immunoassay) for antigens is described. Antigens were reacted with dinitrophenyl monoclonal mouse antibody IgG1and rabbit antibody Fab′-ß-D-galactosidase conjugates. The complex formed of antigens with dinitrophenyl monoclonal mouse antibody IgG1and rabbit antibody Fab′-ß-D-galactosidase conjugates was trapped onto affinity-purified rabbit (antidinitrophenyl bovine serum a1bumin) IgG-coated polystyrene balls. After eliminating excess of the conjugates, the complex was eluted from the polystyrene balls with dinitrophenyl-L-lysine and transfered to clean polystyrene balls coated with affinity-purified rabbit (anti-mouse IgG) IgG. ß-D-Galactosidase activity bound to the (anti-mouse IgG) IgG-coated polystyrene balls was assayed by fluorimetry. Nonspecifically bound ß-D-galactosidase activity considerably decreased with less decrease in specifically bound ß-D-galactosidase activity. As a result, the detection limits of human thyroid-stimulating hormone (0.01 nu, 0.02 amol) and human growth hormone (10 fg, 0.5 amol) by the present enzyme immunoassay were 30-fold lower than those by the conventional enzyme immunoassay, in which antigens were incubated with monoclonal mouse antibody IgG1-coated polystyrene balls and rabbit antibody Fab′-ß-D-galactosidase conjugates.

ISSN:0003-2719    

DOI:10.1080/00032718808055502

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A modified HPTLC technique was applied in investigating venous peripheral blood concentrations of PGE1, FGE2, FGF1α, FGF2α, PGA1 and PGAP2 in three subjects with occupational asthma, undergoing specific bronchial challenge test with chemical sensitizers, as well as in two control subjects, exposed to the same test. The findings obtained show that the technique employed in our study is quite suitable and could be Useful to acquire more information on some biochemical events occurring during asthmatic responses to bronchial challenge.

ISSN:0003-2719    

DOI:10.1080/00032718808055503

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

An optical fibre probe based on glucose dehydrogenase immobilized on nylon was constructed. The probe was used to quantitate glucose through a measurement of the fluorescence of the NADH formed by the enzyme-catalyzed reduction of glucose in the presence of NAD. The probe response was reproducible and displayed good linearity in the concentration range of 1.1 to 11.0 mM glucose. The limit of detection was 0.6 mM glucose. The response was affected by pH and NAD concentration.

ISSN:0003-2719    

DOI:10.1080/00032718808055504

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A simple, rapid and precise high-performance liquid chromatographic assay of meclizine in tablets has been developed. Reversed-phase chromatography was conducted using a mobile phase of acetonitrile and water (30% V/V) and detection at 230 nm. The recovery and coefficient of variation from six placebo tablets containing 25 mg of meclizine were 100.5% and 0.84%, respectively. Replicate regression analyses of three standard plots in the concentration range of 1–12 mcg/ml obtained on three different days gave a correlation coefficient >0.998 and the coefficient of variation of the slopes <1%. The assay was precise within day and between days as indicated by ANOVA test. The recoveries from 10 replicate tablets of the two different commercial meclizine brands were 98.5 and 100.7% of the label amount and their coefficients of variation were 1.16 and 1.71%.

ISSN:0003-2719    

DOI:10.1080/00032718808055505

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Two proposed methods are reported for the quantitation of pirbuterol hydrochloride, namely, (i) colorimetric and (ii) titrimetric methods. The colorimetric method is based on coupling betweem diazotized sulphanilamide and pirbuterol hydrochloride. Under the optimum conditions studied, the coupling product exhibits a maximum at 440 nm. Linear relation between absorbance, A, and concentration of pirbuterol hydrochloride is in the range 5–40 μgml−1. The mean percentage obtained for capsules (ExirelR−15 mg) was 100.8 ± 0.7 whereas mean percentage recovery obtained for the authentic drug was 100.5 ± 0.8.

ISSN:0003-2719    

DOI:10.1080/00032718808055506

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Two spectrophotometric methods are proposed for the simultaneous spectrophotometric determination of phenaaopyridine and nitrofurantoin in tablets. No preliminary separation step is required. The first method involves the use of the modified Vierardt equation as developed by Glenn. The second method is based on the spectral changes induced bg reduction using Zn/HCl; the absorption spectrum of nitrofurantoin completely disappears, Phenazopyridine on the other hand develops a new absorption spectra at 320 nm, the absorbance ratio of the peak at 380 nm to that at 320 nm could be adopted to develop a spectrophotometric method for the determination of both compounds in admixture. The suggested methods were applied to the determination of the two compounds in tablets, and the results obtained were accurate and precise.

ISSN:0003-2719    

DOI:10.1080/00032718808055507

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Brotizolam and Midazolam, psychotropic drugs belonging to thienotriazolodiazepine and imidazobenzodiazepine families, have been determined by flow injection analysis with photometric detection. At pH 7, signals showed to be rectilinear from 1.27 × 10−6M to 1.07 × 10−4M for brotizolam and from 1.53 × 10−6M to 1.07 × 10−4M for midazolam. Methods developed were applied to the determination of both drugs in their formulations (Lendormin and Dormicum).

ISSN:0003-2719    

DOI:10.1080/00032718808055508

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor