125I-labeled gonadoliberin and high specific activity and immunoreactivity: method of iodination and rapid separation.

1980 ◽  
Vol 26 (5) ◽  
pp. 573-578
Author(s):  
A K Sarda ◽  
M A Barnes ◽  
R M Nair
Keyword(s):  
Exchange Resin ◽  
Specific Activity ◽  
High Specific Activity ◽  
Ion Exchange Resin ◽  
Free Form ◽  
Paper Strip ◽  
Peptide Fragments ◽  
Separation And Purification ◽  
Rapid Separation ◽  
Assay Procedure

Abstract We describe optimum conditions for iodinating gonadoliberin with use of relatively large proportions of Na 125I. Products of the iodination are separated on an anion-exchange resin (Amberlite IRA-400). The 125I-labeled gonadoliberin thus obtained has a high specific activity (1400 to 1590 Ci/g); because of the conditions of iodination, we believe that the predominant species of the labeled decapeptide is the mono-iodinated one. Our separation and purification of the labeled substance on ion-exchange resin is rapid, economical, and less cumbersome than the use of a Biogel P-2 column. There is no adsorption of the labeled hormone onto the resin, as evidenced by analytical recovery studies with tritium-labeled gonadoliberin. Paper-strip chromatoelectrophoresis showed no free Na 125I or radiolabeled damaged peptide fragments after purification on the resin. When antiserum was used at a concentration 32-fold that used in the regular assay procedure, only 4% of the radioactivity remained in the free form, indicating the high immunoreactivity of the labeled hormone.

125I-labeled gonadoliberin and high specific activity and immunoreactivity: method of iodination and rapid separation.

1980 ◽  
Vol 26 (5) ◽  
pp. 573-578 ◽  
Author(s):  
A K Sarda ◽  
M A Barnes ◽  
R M Nair
Keyword(s):  
Exchange Resin ◽  
Specific Activity ◽  
High Specific Activity ◽  
Ion Exchange Resin ◽  
Free Form ◽  
Paper Strip ◽  
Peptide Fragments ◽  
Separation And Purification ◽  
Rapid Separation ◽  
Assay Procedure

Abstract We describe optimum conditions for iodinating gonadoliberin with use of relatively large proportions of Na 125I. Products of the iodination are separated on an anion-exchange resin (Amberlite IRA-400). The 125I-labeled gonadoliberin thus obtained has a high specific activity (1400 to 1590 Ci/g); because of the conditions of iodination, we believe that the predominant species of the labeled decapeptide is the mono-iodinated one. Our separation and purification of the labeled substance on ion-exchange resin is rapid, economical, and less cumbersome than the use of a Biogel P-2 column. There is no adsorption of the labeled hormone onto the resin, as evidenced by analytical recovery studies with tritium-labeled gonadoliberin. Paper-strip chromatoelectrophoresis showed no free Na 125I or radiolabeled damaged peptide fragments after purification on the resin. When antiserum was used at a concentration 32-fold that used in the regular assay procedure, only 4% of the radioactivity remained in the free form, indicating the high immunoreactivity of the labeled hormone.

scholarly journals The Phosphorylated Carbohydrate Intermediates from Erythrocytes in Hereditary Spherocytosis

Blood ◽  
1964 ◽  
Vol 23 (4) ◽  
pp. 417-426 ◽  
Author(s):  
A. WILLIAM SHAFER
Keyword(s):  
Ion Exchange ◽  
Exchange Resin ◽  
Hereditary Spherocytosis ◽  
Specific Activity ◽  
Ion Exchange Resin ◽  
Relative Specific Activity ◽  
Definite Difference ◽  
Normal Adults

Abstract The phosphorylated carbohydrate intermediates of erythrocytes from normal adults and from five patients with hereditary spherocytosis (HS) were labeled in vitro with P32 orthophosphate and then separated on columns of ion exchange resin. No qualitative or quantitative differences were found between normal and HS erythrocytes. The relative specific activity of each phosphate of 2, 3 DPG was the same; whereas the phosphate attached to ribose in ADP and ATP was not labeled. The nucleotides were labeled at a much faster rate than DPG. When the erythrocytes were washed 6 or more times, the specific activity of Pi approached that of DPG. No definite difference was found in the rate of labeling of the intermediates from normal and HS erythrocytes.

scholarly journals Separation and Purification of Biogenic 1,3-Propanediol from Fermented Glycerol through Flocculation and Strong Acidic Ion-Exchange Resin

Biomolecules ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1601 ◽  
Author(s):  
Laura Mitrea ◽  
Loredana Florina Leopold ◽  
Cosmina Bouari ◽  
Dan Cristian Vodnar
Keyword(s):  
Secondary Metabolites ◽  
Ion Exchange ◽  
Exchange Resin ◽  
Ion Exchange Resin ◽  
Purification Procedure ◽  
Separation And Purification ◽  
Glycerol Fermentation ◽  
Materials Development ◽  
Plastic Materials ◽  
Fermented Broth

In the present work, was investigated the separation and purification procedure of the biogenic 1,3-propanediol (1,3-PD), which is a well-known valuable compound in terms of bio-based plastic materials development. The biogenic 1,3-PD was obtained as a major metabolite through the glycerol fermentation by Klebsiella pneumoniae DSMZ 2026 and was subjected to separation and purification processes. A strong acidic ion exchange resin in H+ form was used for 1,3-PD purification from the aqueous solution previously obtained by broth flocculation. The eluent volume was investigated considering the removal of the secondary metabolites such as organic acids (acetic, citric, lactic, and succinic acids) and 2,3-butanediol (2,3-BD), and unconsumed glycerol. It was observed that a volume of 84 mL of ethanol 75% loaded with a flow rate of 7 mL/min completely remove the secondary metabolites from 10 mL of concentrated fermented broth, and pure biogenic 1,3-PD was recovered in 128 mL of the eluent.

Fate of Injected Homologous Cr51 Labeled Seroalbumin in Rats

1964 ◽  
Vol 04 (04) ◽  
pp. 364-369
Author(s):  
Leopoldo Anghileri
Keyword(s):  
Decay Rate ◽  
Exchange Resin ◽  
Specific Activity ◽  
High Specific Activity ◽  
Rapid Decrease

SummaryThe absorption and excretion of homologous Chromium-51 seroalbumin was studied in rats.A maximum of activity was observed in intestine, during the first 24 hours and at 27 days. Also a steady high specific activity in spleen and bone was observed.After a rapid decrease of activity during the first three days, it slowed down considerably and decreased almost with the decay rate.During the first 24 hours, this non exchange resin purified Cr51 labeled seroalbumin is excreted mainly through urine and after this point it is through the feces.

THE DEVELOPMENT OF A RADIOIMMUNOASSAY FOR ARGININE-VASOPRESSIN: PRODUCTION OF ANTISERA AND LABELLED HORMONE; SEPARATION TECHNIQUES; SPECIFICITY AND SENSITIVITY OF THE ASSAY IN AQUEOUS SOLUTION

1972 ◽  
Vol 52 (2) ◽  
pp. 279-288 ◽  
Author(s):  
C. R. W. EDWARDS ◽  
T. CHARD ◽  
MURIEL J. KITAU ◽  
MARY L. FORSLING ◽  
J. LANDON
Keyword(s):  
Arginine Vasopressin ◽  
Specific Activity ◽  
Limit Of Detection ◽  
High Specific Activity ◽  
Ion Exchange Resin ◽  
Cross Reactivity ◽  
Amino Acid Sequences ◽  
Simple Method ◽  
Specificity And Sensitivity ◽  
Chloramine T

SUMMARY A radioimmunoassay for vasopressin was developed using antibodies produced against conjugated and non-conjugated arginine vasopressin. Despite the fact that the vasopressin molecule has only eight amino acids, cross reactivity studies showed that these antibodies were specific for different amino acid sequences. Labelled hormone of high specific activity (350–800 μCi/μg) was produced by a modification of the chloramine-T method. Unreacted iodide was removed by the batchwise addition of an ion-exchange resin. Other techniques of purification produced no advantage over this simple method. Several methods of separating antibody-bound and free hormone were studied. All except chromatoelectrophoresis proved satisfactory. Ammonium sulphate or ethanol precipitation of bound hormone was chosen because of simplicity, speed and reproducibility. The lower limit of detection of the assay was 80 pg arginine vasopressin/ml diluent buffer. Therefore an extraction and concentration procedure is necessary for the measurement of basal circulating levels of the hormone.

A micro-assay for estrogen receptor in breast tumor with use of 125I-labeled estradiol.

1982 ◽  
Vol 28 (6) ◽  
pp. 1303-1308 ◽  
Author(s):  
N T Van ◽  
H A Fritsche ◽  
J M Trujillo
Keyword(s):  
Estrogen Receptor ◽  
Breast Tumor ◽  
Specific Activity ◽  
High Specific Activity ◽  
Receptor Protein ◽  
Estrogen Receptor Protein ◽  
Factors Affecting ◽  
Breast Tumor Tissue ◽  
Assay Procedure ◽  
Wet Weight

Abstract The concentration of estrogen receptor protein in breast-tumor tissue is generally expressed in units of femtomoles of estradiol bound by the receptor per milligram of cytosol protein. The sensitivity of the estrogen receptor radioligand assay is therefore related to the specific activity of the steroid label used for the binding assay, the amount of the receptor protein in the volume of cytosol used, and the protein concentration in the cytosol. In this paper, we discuss factors affecting the sensitivity of the estrogen receptor assay and present various approaches for optimizing the assay. We also describe a procedure that involves a radioiodinated estradiol of high specific activity, a micro-technique for preparing tumor cytosol, and a micro-assay procedure with which the estrogen receptor protein can be measured in as little as 50 mg (wet weight) of tissue.

An International Collaborative Study to Investigate Standardisation of Hirudin Potency

1993 ◽  
Vol 69 (05) ◽  
pp. 430-435 ◽  
Author(s):  
Colin Longstaff ◽  
Man-Yu Wong ◽  
Patrick J Gaffney
Keyword(s):  
Specific Activity ◽  
Collaborative Study ◽  
Residual Activity ◽  
Quality Standard ◽  
Upper Limit ◽  
Assay Procedure ◽  
Specific Activities ◽  
International Collaborative ◽  
Range Of Values ◽  
International Collaborative Study

SummaryAn international collaborative study has been carried out to investigate the reproducibility of hirudin assays in 13 laboratories using four recombinant hirudins and one natural, sulphated product. A simple assay procedure was proposed involving the titration of α-thrombin with inhibitor and measurement of residual activity using a chromogenic substrate. A standard α-thrombin preparation was supplied to ensure that this reagent was of uniform quality throughout the study. The method appeared to present no difficulties and laboratories reported similar potencies for the 5 hirudin samples, in line with expected values. This gave 200–222 Thrombin Inhibitory Units/ampoule (TIU/ampoule) of lyophilised hirudin, with geometric coefficient of variation (gcv) values ranging from 10.15–15.97%. This corresponds to specific activities of approximately 14,300–15,900 TIU/mg protein. This is close to the upper limit of previously reported values of specific activity. We conclude that the precision of this determination compared with the wider range of values in the literature (8,000–16,000 thrombin inhibitory units [TIU]/mg) results from the use of good quality standard α-thrombin by all laboratories. This study has important implications for hirudin standardisation.

Effects of Heparin Oligosaccharides with High Affinity for Antithrombin III in Experimental Venous Thrombosis

1982 ◽  
Vol 47 (03) ◽  
pp. 244-248 ◽  
Author(s):  
D P Thomas ◽  
Rosemary E Merton ◽  
T W Barrowcliffe ◽  
L Thunberg ◽  
U Lindahl
Keyword(s):  
Antithrombin Iii ◽  
Specific Activity ◽  
High Specific Activity ◽  
Factor Xa ◽  
Blood Levels ◽  
Thrombin Time ◽  
High Affinity ◽  
Very High

SummaryThe in vitro and in vivo characteristics of two oligosaccharide heparin fragments have been compared to those of unfractionated mucosal heparin. A decasaccharide fragment had essentially no activity by APTT or calcium thrombin time assays in vitro, but possessed very high specific activity by anti-Factor Xa assays. When injected into rabbits at doses of up to 80 ¼g/kg, this fragment was relatively ineffective in impairing stasis thrombosis despite producing high blood levels by anti-Xa assays. A 16-18 monosaccharide fragment had even higher specific activity (almost 2000 iu/mg) by chromogenic substrate anti-Xa assay, with minimal activity by APTT. When injected in vivo, this fragment gave low blood levels by APTT, very high anti-Xa levels, and was more effective in preventing thrombosis than the decasaccharide fragment. However, in comparison with unfractionated heparin, the 16-18 monosaccharide fragment was only partially effective in preventing thrombosis, despite producing much higher blood levels by anti-Xa assays.It is concluded that the high-affinity binding of a heparin fragment to antithrombin III does not by itself impair venous thrombogenesis, and that the anti-Factor Xa activity of heparin is only a partial expression of its therapeutic potential.

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