Stable Plasma Sample Storage in Acetonitrile for Angiotensin and Aldosterone Analysis

2020 ◽  
Author(s):  
Xuefei Wei ◽  
Yanyang Wang ◽  
Wenbo Zhu ◽  
Jingjing Li ◽  
Lu Peng ◽  
...  
Keyword(s):  
Room Temperature ◽  
Plasma Sample ◽  
Sample Storage ◽  
Angiotensin I ◽  
Storage Method ◽  
Collaborative Studies ◽  
Stable Plasma

Abstract Background Angiotensin I, II (AI, AII) and aldosterone are unstable in plasma specimens at room temperature, making it difficult for collect samples for remote regions in centralized and collaborative studies. Here we introduce a stable storage method which do not require cold conditions.. Methods Acetonitrile was added to the plasma to 60%, and then the supernatants were kept at 4°C and room temperature for 0, 1, 2, 3, 10 and 30 days. AI, AII and aldosterone were extracted and analyzed by chemiluminescence immunoassays. Results AI, AII and aldosterone were well retained in the supernatant under this method. The intra- and inter-day CVs of this method were all below 10%. The levels of AI, AII and aldosterone by this method remained stable for 30 days at room temperature. Conclusion Addition of 60% acetonitrile in the plasma provides a stable storage method for clinical AI, AII and aldosterone.

scholarly journals The effect of storage conditions on samples for the evaluation of copper status in blesbok (Damaliscus pygargus phillipsi)

2002 ◽  
Vol 73 (3) ◽  
Author(s):  
M. Quan ◽  
M.S. Mulders ◽  
D.G.A. Meltzer
Keyword(s):  
Superoxide Dismutase ◽  
Liquid Nitrogen ◽  
Liver Tissue ◽  
Room Temperature ◽  
Storage Conditions ◽  
Superoxide Dismutase Activity ◽  
Activity Levels ◽  
Sample Storage ◽  
Live Animal ◽  
Jersey Cows

Investigaltions to determine the effect of sample storage on the concentration of copper in liver tissue and on the activity of erythrocyte superoxide dismutase were undertaken in preparation for a study of blesbok (Damaliscus pygargus phillipsi) that were suspected to be suffering from copper deficiency. Two liver samples were collected from each of 20 culled blesbok in a manner that simulated the collection of biopsies from the live animal. These samples were stored either in 10 % formalin or frozen at -20 °C until analysed 4 1/2 months later. The effect of different methods of sample storage on superoxide dismutase activity was determined. Erythrocytes collected from 3 Jersey cows and 5 culled blesbok were washed and divided into 0.5m portions, stored at room temperature (~20 °C), in a refrigerator (4 °C), frozen at -20 °C in a freezer, and in liquid nitrogen (-200 °C). An analysis of superoxide dismutase activity was undertaken using a commercial assay kit at intervals of 2-4 days until the levels of activity had fallen significantly. The copper concentration in formalin-preserved liver samples was significantly lower than that measured in frozen liver tissue apparently as a result of leaching. The activity of superoxide dismutase in cattle blood was unchanged for 4 days at room temperature but fell appreciably after 2 days at 4 °C and -20 °C. Enzyme activity remained unchanged for 200 days in erythrocytes stored in liquid nitrogen. Superoxide dismutase activity levels in healthy blesbok were considerably lower than those measured in Jersey cows and remained unaffected for up to 6 days in samples stored at 4 °C and 20 °C. The level of activity fell significantly thereafter. Samples stored in liquid nitrogen were unchanged after 40 days.

DEVELOPMENT OF A SIMPLE FACTOR VIII-ASSAY FOR CLINICAL USE

1987 ◽  
Author(s):  
R Wagenvoord ◽  
H Hendrix ◽  
H C Hemker
Keyword(s):  
Factor Viii ◽  
Room Temperature ◽  
Plasma Sample ◽  
Factor Xa ◽  
Factor X ◽  
Activation Time ◽  
Simple Factor ◽  
Working Day ◽  
Working Procedure

We have developed an assay for the determination of factor VIII in human plasma. The criteria that such an assay must fulfil are: the method should be simple, the reagents should be stable for several hours at room temperature, the method should be sensitive and linear in the amount of factor VIII. The assay we have developed fulfils all these criteria.The working procedure is simple. Both a lyophilized factor VIII assay (containing factor IXa, thrombin, phospholipids and Ca++) and lyophilized factor X are reconstituted with water. A reaction tube is filled with 100 pi factor VIII assay, prewarmed at 25° or 37 °C, then 100 pi of a diluted (10-20 times) plasma sample is added (t = 0) and after 30 seconds activation time the reaction is started with 100 pi factor X. After 1-2 minutes a sample is taken and diluted in an EDTA-containing buffer to stop the reaction. The formed factor Xa is meausured with a FXa-substrate from which p-nitroaniline will be split, causing an increase of the A405nm. The lyophilized reagents are stable for several months (at least) and after reconstitution they do not loose activity during a whole working day. The sensitivity of the method Is high. A plasma containing 1% factor VIII gives an increase in absorption of three to four times of a fully factor VIII deficient plasma. Extensive studies have shown that a complete linearity excists between 0 - 200% factor VIII in the plasma and the increase of the A405nm

Metastable Superstructures in RuSr2Gd1.4Ce0.6Cu2O10-δ?Superconductor Based on TEM Observation at Room Temperature

2001 ◽  
Vol 689 ◽  
Author(s):  
Li Yang ◽  
J. M. Vieira ◽  
Kaibin Tang ◽  
Guien Zhou
Keyword(s):  
Electron Beam ◽  
Electron Diffraction ◽  
Room Temperature ◽  
Storage Time ◽  
Point Of View ◽  
Tetragonal Symmetry ◽  
Sample Storage ◽  
Unconventional Superconductor ◽  
Fluorite Type ◽  
Structural Point

ABSTRACTThree types of metastable modulations in Ru-based superconductor RuSr2Gd1.4Ce0.6Cu2O10-δ are observed by electron diffraction at room temperature and reported in this paper. The modulations are sensitive to the irradiation of the electron beam and the sample storage time. Having the tetragonal symmetry (I4/mmm) with a=0.384nm, c=2.864nm, the structure of RuSr2Gd1.4Ce0.6Cu2O10-δ?resembles that of YBa2Cu3O7-δ by inserting a fluorite type Gd1.4Ce0.6O2 layer instead of the Y layer and Ru ions residing in the Cu(1) site. In this compound, superconductivity is confined to the CuO2 layer while magnetism stems from the RuO2 layer. The metastable modulations display the interaction between the two layers from the structural point of view. The results suggest that although, superconductivity and magnetism are decoupled from each other in the unconventional superconductor, the effect may be limited by metastable lattice modulation.

Should blood samples for assay of plasma renin activity be chilled?

1978 ◽  
Vol 24 (11) ◽  
pp. 2042-2043 ◽  
Author(s):  
R L Emanuel ◽  
G H Williams
Keyword(s):  
Plasma Renin Activity ◽  
Room Temperature ◽  
Plasma Renin ◽  
The Other ◽  
Renin Activity ◽  
Angiotensin I ◽  
Blood Samples ◽  
Hypertensive Patients

Abstract Collecting blood on ice for renin determination reportedly may produce falsely high results. To assess the probability of this occurring under actual collection conditions, we measured renin activity in duplicate aliquots of plasma from blood samples from 25 hypertensive patients, both supine and upright, and in 10 supine normotensive controls. One aliquot of the blood was collected on ice and processed at 4 degrees C, the other at room temperature. The two aliquots showed no significant differences in renin activity. If anything, values for samples collected at room temperature were higher. Repeat determination on the same specimens stored at--20 degrees C for nine and 12 months revealed no significant changes in results for any samples, although the amount of angiotensin I found in the sample before incubation at 37 degrees C significantly increased. We conclude that it makes little difference at what temperature one collects blood for renin determination, but because of the wide fluctuations in "room" temperature we recommend that blood samples be collected on ice.

Gel Entrapment of Antibody: A New Strategy for Facilitating Both Manual and Automated Radioimmunoassay

1973 ◽  
Vol 19 (12) ◽  
pp. 1339-1344 ◽  
Author(s):  
Stuart J Updike ◽  
John D Simmons ◽  
Douglas H Grant ◽  
Judith A Magnuson ◽  
Theodore L Goodfriend
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Room Temperature ◽  
Solid Phase ◽  
Binding Activity ◽  
Angiotensin I ◽  
Chromatographic Columns ◽  
New Strategy ◽  
Sample Application ◽  
Solid Phase Binding

Abstract A technique of radioimmunoassay is presented that eliminates pipetting and centrifugation, and excludes interferences by high-molecular-weight materials from the incubation and separation steps. A solid-phase binding reagent is prepared by first entrapping antibody in polyacrylamide gel. This gel is then fragmented, sieved, dried with ethanol or lyophilized, and placed in miniature disposable chromatographic columns. Application of the sample to the intra-gel column compartment is determined by the water regain of the gel. This pipetless method of sample application depends on reproducible aliquots of dry gel particles in every column. A method for preloading radiolabeled hormone and standard hormone into the column is also described. This technique has been successfully applied to the assay of angiotensin I and insulin. Dry antibody—gel stored at room temperature for 26 months has not shown loss of binding activity.

scholarly journals INTERACTIVE EFFECTS OF SIZE, STORAGE METHOD AND DURATION ON QUALITY AND PHYSICAL CHARACTERISTICS OF TABLE EGGS

2021 ◽  
Vol 23 (1) ◽  
pp. 76-81
Author(s):  
S. O. KEMBI ◽  
A. A. OSOKOMAIYA
Keyword(s):  
Specific Gravity ◽  
Egg Size ◽  
Room Temperature ◽  
Egg Quality ◽  
Interactive Effects ◽  
Quality Changes ◽  
Quality Indices ◽  
Storage Method ◽  
Weight Losses ◽  
Long Storage

A total of 252 fresh table eggs sorted into standard, large and extra-large sizes were but.either refrigerated or held at room temperature and used to study their weekly weight losses (WL), specific gravity (SG), egg index (EI), yolk index (YI) and albumen height (AH) over a six week period. The results showed that among  room-stored eggs there were declines (P<0.01) AH, YI, SG and El but an increase in WL with increased egg size. Similar trends in response  to long storage were observed except that EI not affected (P>0.05). The depressive influences of long storage and larger sizes on egg quality observed in the room stored eggs diminished with refrigeration. The general patterns of quality deterioration show that,  irrespective of egg size, six-week refrigerated eggs had better quality indices than one-week room-stored eggs. There was no significant (P>0.05) influence of egg size on quality changes during storage Based on the result it was included  that in the absence of refrigeration and when eggs are sold in assorted sizes, table eggs should be consumed within 2 weeks of lay and larger eggs should be used first. 

QUANTITATION OF CARVEDILOL OXIDATIVE METABOLITES IN HUMAN PLASMA USING LIQUID CHROMATOGRAPHY TANDEM MASS SPECTROMETRY

INDIAN DRUGS ◽  
2012 ◽  
Vol 49 (02) ◽  
pp. 37-44
Author(s):  
J Valarmathy ◽  
◽  
T. Sudha ◽  
K. L. Kumar ◽  
S. L Joshua
Keyword(s):  
Human Plasma ◽  
Room Temperature ◽  
Plasma Sample ◽  
Liquid Extraction ◽  
Liquid Liquid Extraction ◽  
Chromatography Tandem Mass Spectrometry ◽  
Oxidative Metabolites ◽  
Liquid Chromatography Tandem Mass ◽  
Assay Precision

A sensitive and efficient method was developed for the determination of carvedilol and its metabolite in human plasma by LC-MS/MS. Plasma samples were hydrolysed with beta-glucuronidase and the target compounds were extracted with liquid liquid extraction using diethyl ether in dichloro methane as solvent. The extracts were completely derivatized and analysed by LC-MS/MS. The linearity of the assay ranges from 0.250 ng/mL to 200.0 ng/mL for carvedilol and from 0.500 ng/mL to 30.0 ng/mL for 4-hydroxy carvedilol. The absolute recovery of carvedilol and its metabolite added to blank plasma sample was 70.28 82.90%. The reproducibility was from 0.96 to 8.28 for the intraday assay and from 1.65 to 6.09 for the interday assay precision. Repetitive thawing and freezing did not have an affect on metabolite through a minimum of three cycles. Thawed samples remaining in plasma for 4h before extraction were with 5% of theoretical value. Stability of the extracted samples on the auto sampler at room temperature was evaluated for 34 h and was observed to with in 12% of a fresh analytical sample for 4 hydroxy carvedilol. The proposed LC-MS/MS method was effective for the determination of carvedilol and it metabolite in human plasma.

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