scholarly journals Observations on the use of solid-phase-coupled antibodies in the radioimmunoassay of human placental lactogen

1974 ◽  
Vol 137 (3) ◽  
pp. 469-476 ◽  
Author(s):  
Jacqueline Gardner ◽  
Gordon Bailey ◽  
Timothy Chard
Keyword(s):  
Solid Phase ◽  
Coupling Reaction ◽  
High Sensitivity ◽  
Comparative Assessment ◽  
Placental Lactogen ◽  
Affinity Constant ◽  
Considerable Proportion ◽  
Lower Sensitivity ◽  
Human Placental Lactogen ◽  
Free Antigen

A detailed comparative assessment was made of the use of solid-phase-coupled antibodies in radioimmunoassay, by using an assay for human placental lactogen as a model system. The major advantages of the solid-phase technique are: (1) in common with the use of a second antibody, it is universally applicable; (2) separation can be carried out rapidly; (3) in contrast with some other techniques, the separation of antibody-bound and free antigen is virtually complete. The disadvantages when compared with other procedures are: (1) a considerable proportion of the antibody may be lost during the initial coupling reaction; (2) the tubes must be continuously mixed during incubation, and much effort is expended in removing and replacing the caps; (3) there is a decrease in the apparent affinity constant of the antibody after coupling, which is reflected in a lower sensitivity of the assay system. It is concluded that solid-phase antibodies are of greatest value in those systems in which the supply of antiserum is abundant, and in which the achievement of high sensitivity is not a requirement.

Centrifugal analyzer used for enzyme immunoassay of progesterone and choriomammotropin.

1983 ◽  
Vol 29 (2) ◽  
pp. 302-304 ◽  
Author(s):  
B Terouanne ◽  
J Marchand ◽  
C Calzolari ◽  
J Monnier ◽  
J C Nicolas ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Affinity Chromatography ◽  
Enzyme Immunoassay ◽  
Gel Filtration ◽  
Placental Lactogen ◽  
Human Placental Lactogen ◽  
Rapid Separation ◽  
Enzyme Conjugate ◽  
Enzyme Label ◽  
Free Antigen

Abstract Recently we developed an enzyme immunoassay involving the use of steroid delta-isomerase (EC 5.3.3.1) as enzyme label and exclusion-affinity chromatography for rapid separation of free antigen-enzyme conjugate that bound to antibodies (J. Immunol. Methods 35: 267-284, 1980). Here we describe an automated version of this procedure, for immunoassay of progesterone and choriomammotropin (human placental lactogen) in serum with the use of a centrifugal analyzer. After incubation, suitable dilutions of sera or extract plus antiserum, conjugate, and double antibody were filtered on an estradiol affinity gel-filtration column; the enzyme activity of the filtrates was determined with the centrifugal analyzer. Results correlate well with those obtained by radioimmunoassay: r (progesterone) = 0.980, r (choriomammotropin) = 0.940. The within-run and between-run precision, specificity, sensitivity, accuracy, and speed of this system make it a useful tool for immunoassay.

Solid-phase radioimmunoassay for human placental lactogen in serum.

1983 ◽  
Vol 29 (1) ◽  
pp. 168-170 ◽  
Author(s):  
G Samuel ◽  
N Sivaprasad ◽  
K B Shah ◽  
R S Mani
Keyword(s):  
Ionic Strength ◽  
Incubation Time ◽  
Solid Phase ◽  
Placental Lactogen ◽  
Human Placental Lactogen ◽  
Optimum Conditions ◽  
Nonspecific Adsorption ◽  
Assay Tube ◽  
Solid Phase Radioimmunoassay ◽  
Assay Technique

Abstract We report a solid-phase radioimmunoassay for human placental lactogen, in which antibody-coated polystyrene tubes and polyurethane sponges are used. Incubation time and temperature, ionic strength of buffer, and nonspecific adsorption have been evaluated for optimum conditions required for routine clinical assays. The validity of the assay technique has been ascertained by its specificity, reproducibility, and recovery. The sensitivity of this method is 0.4 ng of placental lactogen per assay tube.

scholarly journals A Single LC-MS/MS Analysis to Quantify CoA Biosynthetic Intermediates and Short-Chain Acyl CoAs

Metabolites ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 468
Author(s):  
Anthony E. Jones ◽  
Nataly J. Arias ◽  
Aracely Acevedo ◽  
Srinivasa T. Reddy ◽  
Ajit S. Divakaruni ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Sample Preparation ◽  
Biosynthetic Pathway ◽  
Solid Phase ◽  
High Sensitivity ◽  
Short Chain ◽  
Extraction Column ◽  
Chain Acyl ◽  
Precision And Accuracy ◽  
Mass Spectrometry Mass Spectrometry

Coenzyme A (CoA) is an essential cofactor for dozens of reactions in intermediary metabolism. Dysregulation of CoA synthesis or acyl CoA metabolism can result in metabolic or neurodegenerative disease. Although several methods use liquid chromatography coupled with mass spectrometry/mass spectrometry (LC-MS/MS) to quantify acyl CoA levels in biological samples, few allow for simultaneous measurement of intermediates in the CoA biosynthetic pathway. Here we describe a simple sample preparation and LC-MS/MS method that can measure both short-chain acyl CoAs and biosynthetic precursors of CoA. The method does not require use of a solid phase extraction column during sample preparation and exhibits high sensitivity, precision, and accuracy. It reproduces expected changes from known effectors of cellular CoA homeostasis and helps clarify the mechanism by which excess concentrations of etomoxir reduce intracellular CoA levels.

scholarly journals Synthetic Amphipathic Peptides Resembling Apolipoproteins Stimulate the Release of Human Placental Lactogen

1989 ◽  
Vol 264 (16) ◽  
pp. 9215-9219
Author(s):  
E V Jorgensen ◽  
G M Anantharamaiah ◽  
J P Segrest ◽  
J T Gwynne ◽  
S Handwerger
Keyword(s):  
Placental Lactogen ◽  
Human Placental Lactogen ◽  
Amphipathic Peptides

scholarly journals Multiple origins of transcription for the human placental lactogen genes.

1984 ◽  
Vol 259 (23) ◽  
pp. 14642-14646 ◽  
Author(s):  
C S Selvanayagam ◽  
S Y Tsai ◽  
M J Tsai ◽  
P Selvanayagam ◽  
G F Saunders
Keyword(s):  
Placental Lactogen ◽  
Human Placental Lactogen ◽  
Multiple Origins

scholarly journals Recombinant hormones from fragments of human growth hormone and human placental lactogen.

1981 ◽  
Vol 256 (1) ◽  
pp. 296-300
Author(s):  
J. Russell ◽  
L.M. Sherwood ◽  
K. Kowalski ◽  
A.B. Schneider
Keyword(s):  
Growth Hormone ◽  
Human Growth Hormone ◽  
Human Growth ◽  
Placental Lactogen ◽  
Human Placental Lactogen

scholarly journals 60–700 K CTAT and PTAT Temperature Sensors with 4H-SiC Schottky Diodes

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 942
Author(s):  
Razvan Pascu ◽  
Gheorghe Pristavu ◽  
Gheorghe Brezeanu ◽  
Florin Draghici ◽  
Philippe Godignon ◽  
...  
Keyword(s):  
Low Cost ◽  
Schottky Diodes ◽  
Schottky Contact ◽  
High Sensitivity ◽  
Xrd Analysis ◽  
Absolute Temperature ◽  
Lower Sensitivity ◽  
Readout Circuit ◽  
Sensing Element ◽  
High Performing

A SiC Schottky dual-diode temperature-sensing element, suitable for both complementary variation of VF with absolute temperature (CTAT) and differential proportional to absolute temperature (PTAT) sensors, is demonstrated over 60–700 K, currently the widest range reported. The structure’s layout places the two identical diodes in close, symmetrical proximity. A stable and high-barrier Schottky contact based on Ni, annealed at 750 °C, is used. XRD analysis evinced the even distribution of Ni2Si over the entire Schottky contact area. Forward measurements in the 60–700 K range indicate nearly identical characteristics for the dual-diodes, with only minor inhomogeneity. Our parallel diode (p-diode) model is used to parameterize experimental curves and evaluate sensing performances over this far-reaching domain. High sensitivity, upwards of 2.32 mV/K, is obtained, with satisfactory linearity (R2 reaching 99.80%) for the CTAT sensor, even down to 60 K. The PTAT differential version boasts increased linearity, up to 99.95%. The lower sensitivity is, in this case, compensated by using a high-performing, low-cost readout circuit, leading to a peak 14.91 mV/K, without influencing linearity.

scholarly journals Transcriptional products of the human placental lactogen gene.

1982 ◽  
Vol 257 (20) ◽  
pp. 12399-12404 ◽  
Author(s):  
H A Barrera-Saldaña ◽  
D L Robberson ◽  
G F Saunders
Keyword(s):  
Placental Lactogen ◽  
Human Placental Lactogen
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