Column affinity chromatography for bound/free separation in ligand assays. I. Radioimmunoassay of choriomammotropin (human placental lactogen).

Abstract A method is described for separating antibody-bound from free fractions in ligand assays by column affinity chromatography, and its application to radioimmunoassay of choriomammotropin. In the method, 70 x 10 mm (i.d.) polypropylene columns containing about 150 mg of immunosorbent (goat anti-rabbit gamma-globulins covalently linked to Sepharose CL-4B) are used. Standards or unknowns, tracer and antiserum, pipetted into bottom-capped columns, are kept separated from the immunosorbent bed by a porous polyethylene disc and allowed to react for 15 min at room temperature. The reaction mixture is then allowed to pass through the columns by removing the bottom caps. Free antigen is eluted by washing the column, and discarded; antibody-bound fractions remain bound to the immunosorbent. The radioactivity in the columns is counted. The major advantages of the present technique, arising from the liquid-phase reaction combined with the solid-phase separation by column affinity chromatography, are the very low nonspecific binding (less than 1%), good sensitivity (0.02 mg/L), good precision (CV 3.4%), and simple and fast (30-min) assay. For 50 clinical samples so assayed (gamma) and compared with a polyethylene glycol precipitation technique (x), the regression equation was: y - 0.14 + 0.98x (r = 0.994). The assay method was clinical validated by 3493 determinations.

Download Full-text

Enzyme-linked immunosorbent choriomammotropin assay.

Clinical Chemistry ◽

10.1093/clinchem/25.2.227 ◽

1979 ◽

Vol 25 (2) ◽

pp. 227-229 ◽

Cited By ~ 4

Author(s):

D Dittmar ◽

N Monji ◽

A Cid ◽

H Malkus ◽

A Castro

Keyword(s):

Immunosorbent Assay ◽

Coefficient Of Variation ◽

Regression Equation ◽

Placental Lactogen ◽

Clinical Samples ◽

Enzyme Linked Immunosorbent Assay ◽

Good Precision ◽

Human Placental Lactogen ◽

Mean Concentration ◽

Beta Galactosidase

Abstract We have devloped an enzyme-linked immunosorbent assay for determining choriomammotropin (human placental lactogen) in serum. Unlabeled hormone competes with choriomammotropin-beta-galactosidase conjugate for antibody bound to polystyrene tubes. The entire assay can be performed in 2.5 h with good precision. The coefficient of variation for one sample with a mean concentration of 5.6 mg/L, assayed 10 times on the same day, was 5.7%. The coefficient of variation for nine samples (3.5 to 9.0 mg/L) assayed on five different days was 7.9%. Forty-eight clinical samples were assayed (y) and compared with results obtained by radial immunodiffusion (x). The resulting regression equation was: y = 1.05x + 0.78; r = 0.91.

Download Full-text

Highly specific antisera against native ovine follitropin (oFSH) obtained from crude antisera by affinity chromatography on solid-phase undissociable lutropin (LH) column

Acta Endocrinologica ◽

10.1530/acta.0.1060038 ◽

1984 ◽

Vol 106 (1) ◽

pp. 38-42 ◽

Cited By ~ 3

Author(s):

J. C. Poirier ◽

Y. Combarnous ◽

M. R. Blanc

Keyword(s):

Affinity Chromatography ◽

Solid Phase ◽

Cross Reaction ◽

Affinity Column ◽

Glycoprotein Hormones ◽

Α Subunit ◽

Specific Antibodies ◽

Apparent Loss ◽

Specific Antisera ◽

Covalently Linked

Abstract. Antibodies recognizing determinants of the α-subunit, which is common to all glycoprotein hormones, were eliminated from antisera against native oFSH by affinity chromatography. Since the free α-subunit is immunologically different from the α-subunit in the intact hormone, we did not use an α-subunit affinity column. Instead, the antisera were applied to an LH affinity column. However, because intact LH dissociates in the conditions used to elute the purified antibodies, we prepared an LH derivative with covalently-linked subunits and coupled it to gel matrix. By this method oFSH antisera were freed from their non-specific antibodies. The cross-reaction of ovine lutropin in the oFSH radioimmunoassay (RIA) was lowered from 2% to less than 0.1%. Moreover, as the columns can be used repeatedly over long periods with no apparent loss of efficiency, large volumes of antiserum can be treated in this manner.

Download Full-text

Mechanism of the solid-phase reaction of magnesium with organic halides

Journal of Organometallic Chemistry ◽

10.1016/s0022-328x(00)98860-0 ◽

1983 ◽

Vol 243 (1) ◽

pp. 123-129 ◽

Cited By ~ 10

Author(s):

G Sergeev

Keyword(s):

Solid Phase ◽

Solid Phase Reaction ◽

Phase Reaction ◽

Organic Halides

Download Full-text

Bioanalytical method development and validation of simultaneous analysis of telmisartan and hydrochlorthiazide in human plasma using LC-MS/MS

International Journal of Bioassays ◽

10.21746/ijbio.2016.03.003 ◽

2016 ◽

Vol 5 (03) ◽

pp. 4862 ◽

Cited By ~ 1

Author(s):

Mathew George* ◽

Lincy Joseph ◽

Arpit Kumar Jain ◽

Anju V.

Keyword(s):

Human Plasma ◽

Retention Time ◽

High Performance ◽

Method Development ◽

Matrix Effects ◽

Solid Phase ◽

Internal Standard ◽

Assay Method ◽

Buffer System ◽

Internal Standards

A simple, sensitive, rapid and economic high performance thin layer chromatographic method and a mass spectroscopic assay method has been developed for the quantification of telmisartan and hydrochlorthiazide combination in human plasma. The internal standards and analytes were extracted from human plasma by solid-phase extraction with HLB Oasis1cc (30mg) catridges. The scanning and optimization for the samples are done using methanol: water (50:50). The samples were chromatographed using reverse phase chromatography with C-18 column of different manufacturers like Ascentis C18 (150×4. 6, 5µ) using the buffer system Acetonitrile: Buffer (80:20%v/v) which consist of 2±0. 1Mm ammonium format at a flow rate of 0. 7ml/min at a column oven temperature 35±10c. The internal standard used was hydrochlorthiazide13c1, d2 and telmisartand3. The extraction techniques include conditioning, loading, washing and elution, drying followed by reconstitution of the dried samples. The volume injected was 10µl with the retention time of 3-4 min for telmisartan, 1-2 min for hydrochlorthiazide and for the internal standards the retention time was 3-4 min for telmisartand3 and 1-2 min for hydrochlorthiazide c13d2. The rinsing solution was Acetonitrile: HPLC grade water in the ratio (50:50). The above developed method was validated using various parameters like selectivity and sensitivity, accuracy and precision, matrix effects, % recovery and various stability studies. The method was proved to be sensitive, accurate, precise and reproducible. The preparation showed high recovery for the quantitative determination of telmisartan and hydrochlorthiazide in human plasma.

Download Full-text

Fe3O4@C Nanoparticles Synthesized by In Situ Solid-Phase Method for Removal of Methylene Blue

Nanomaterials ◽

10.3390/nano11020330 ◽

2021 ◽

Vol 11 (2) ◽

pp. 330

Author(s):

Hengli Xiang ◽

Genkuan Ren ◽

Yanjun Zhong ◽

Dehua Xu ◽

Zhiye Zhang ◽

...

Keyword(s):

Methylene Blue ◽

Solid Phase ◽

Raw Materials ◽

Phase Method ◽

Maximum Adsorption Capacity ◽

High Catalytic Activity ◽

Solid Phase Reaction ◽

Phase Reaction ◽

High Concentrations

Fe3O4@C nanoparticles were prepared by an in situ, solid-phase reaction, without any precursor, using FeSO4, FeS2, and PVP K30 as raw materials. The nanoparticles were utilized to decolorize high concentrations methylene blue (MB). The results indicated that the maximum adsorption capacity of the Fe3O4@C nanoparticles was 18.52 mg/g, and that the adsorption process was exothermic. Additionally, by employing H2O2 as the initiator of a Fenton-like reaction, the removal efficiency of 100 mg/L MB reached ~99% with Fe3O4@C nanoparticles, while that of MB was only ~34% using pure Fe3O4 nanoparticles. The mechanism of H2O2 activated on the Fe3O4@C nanoparticles and the possible degradation pathways of MB are discussed. The Fe3O4@C nanoparticles retained high catalytic activity after five usage cycles. This work describes a facile method for producing Fe3O4@C nanoparticles with excellent catalytic reactivity, and therefore, represents a promising approach for the industrial production of Fe3O4@C nanoparticles for the treatment of high concentrations of dyes in wastewater.

Download Full-text

Microstructure and Mechanical Properties of ZrB2/h-BN Multiphase Ceramics by Low-Temperature Reactive Sintering

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.697.510 ◽

2016 ◽

Vol 697 ◽

pp. 510-514 ◽

Cited By ~ 1

Author(s):

Feng Rui Zhai ◽

Ke Shan ◽

Ruo Meng Xu ◽

Min Lu ◽

Zhong Zhou Yi ◽

...

Keyword(s):

Mechanical Properties ◽

Relative Density ◽

Fracture Strength ◽

Solid Phase ◽

Raw Materials ◽

Solid Phase Reaction ◽

Phase Reaction ◽

Microstructure And Mechanical Properties ◽

Multiphase Ceramics ◽

Strength And Toughness

In the present paper, the ZrB2/h-BN multiphase ceramics were fabricated by SPS (spark plasma sintering) technology at lower sintering temperature using h-BN, ZrO2, AlN and Si as raw materials and B2O3 as a sintering aid. The phase constitution and microstructure of specimens were analyzed by XRD and SEM. Moreover, the effects of different sintering pressures on the densification, microstructure and mechanical properties of ZrB2/h-BN multiphase ceramics were also systematically investigated. The results show that the ZrB2 was obtained through solid phase reaction at different sintering pressures, and increasing sintering pressure could accelerate the formation of ZrB2 phase. As the sintering pressure increasing, the fracture strength and toughness of the sintered samples had a similar increasing tendency as the relative density. The better comprehensive properties were obtained at given sintering pressure of 50MPa, and the relative density, fracture strength and toughness reached about 93.4%, 321MPa and 3.3MPa·m1/2, respectively. The SEM analysis shows that the h-BN grains were fine and uniform, and the effect of sintering pressure on grain size was inconspicuous. The distribution of grain is random cross array, and the fracture texture was more obvious with the increase of sintering pressure. The fracture mode of sintered samples remained intergranular fracture mechanism as sintering pressure changed, and the grain refinement, grain pullout and crack deflection helped to increase the mechanical properties.

Download Full-text