Effect of Freezing and Thawing of Serum on the Immunoassay of Lipoprotein(a)

1992 ◽  
Vol 38 (9) ◽  
pp. 1873-1877 ◽  
Author(s):  
D S Sgoutas ◽  
T Tuten
Keyword(s):  
Room Temperature ◽  
Enzyme Linked Immunosorbent Assay ◽  
Freezing And Thawing ◽  
Serum Samples ◽  
Lipoprotein A ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Quick Freezing ◽  
Freeze Thaw Cycle

Abstract We studied the effect of freezing and thawing of serum on the determination of lipoprotein(a) [Lp(a)] with a commercial enzyme-linked immunosorbent assay (ELISA) and an immunoturbidimetric assay (ITA). Portions of sera from 11 apparently healthy persons and pooled sera, from an additional 10 subjects were frozen at either -20 or -70 degrees C and thawed at room temperature. Cycles of freezing and thawing were repeated during the experiments (1 month). Samples were assayed for Lp(a) after thawing. Pooled sera were subjected to quick freezing at -70 degrees C and thawing at room temperature in cycles. Results show a significant (P less than 0.05) decrease in Lp(a) concentration in sera subjected to freezing and thawing. Samples thawed from -20 degrees C gave concentrations by ELISA that were significantly lower than those of fresh samples after one freeze-thaw cycle. By ITA the decrease was significant only after two cycles. In specimens frozen at -70 degrees C, Lp(a) concentrations determined by ELISA decreased after two cycles, and by ITA after three freeze-thaw cycles. Serum samples subjected to quick freezing at -70 degrees C and thawing did not show significant decreases in Lp(a) immunoreactivity during four cycles. Immunoreactivity of Lp(a) in samples stored at 4 degrees C decreased after 6 days but fell faster in serum samples subjected to freezing and thawing before storage at 4 degrees C.

scholarly journals PSIV-25 Effect of Various Handling Methods of Plasma and Serum Samples on Pregnancy Associated Glycoprotein Concentrations

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 289-290
Author(s):  
Grace M Wesson ◽  
Lohana Fernandez ◽  
Rebecca K Poole ◽  
Gessica A Franco ◽  
Sydney T Reese ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Plasma Samples ◽  
Freezing And Thawing ◽  
Serum Samples ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Repeated Freezing ◽  
Pregnancy Status ◽  
Handling Methods

Abstract Pregnancy associated glycoproteins (PAG) can be used as a biomarker for early pregnancy diagnosis, so accurate and consistent PAG detection is critical. The objective of this study was to determine if plasma and serum PAG concentrations were altered when centrifugation occurred at different times post-collection, when subjected to repeated freezing and thawing, and when monoclonal antibodies were kept in frequently or infrequently opened containers. Plasma (n = 4) and serum (n = 4) samples were collected from two open cows and two pregnant cows 28 days after artificial insemination. Pregnancy status was determined via transrectal ultrasonography. Plasma and serum samples were evenly separated and either centrifuged on the day of collection, or placed at 4°C and centrifuged the next day. An in-house PAG ELISA was performed on all samples before freezing (NOTHAW), after being frozen for one week (INTACT), after one freeze/thaw cycle (THAW1), two freeze/thaw cycles (THAW2), and three freeze/thaw cycles (THAW3). Data were analyzed using one-way ANOVA (GLM procedure, SAS 9.4). All samples from open cows were below the baseline of the assay. For pregnant cows, plasma samples had greater PAG concentrations than serum samples (11.84 vs 3.30 ± 0.66 ng/mL, respectively, P < 0.05). No differences were observed for day of centrifugation in both plasma and serum samples (P = 0.50 and P = 0.60, respectively) and in handling of monoclonal antibodies (P = 0.90). Freezing and thawing did not impact PAG concentrations in plasma samples (P = 0.19), but did alter serum concentrations (P = 0.01). Specifically, THAW1 (1.98 ng/mL) and THAW2 (1.42 ng/mL) serum PAG concentrations were lower compared to NOTHAW, THAW3, and INTACT samples (4.66, 4.85, and 3.57 ng/mL, respectively). Based on these data, plasma yields more consistent results than serum, even after several freeze-thaw cycles, and handling of monoclonal antibodies or time of centrifugation has no significant effect on measured PAG.

scholarly journals Performance of soluble Klotho assays in clinical samples of kidney disease

2019 ◽  
Vol 13 (2) ◽  
pp. 235-244 ◽  
Author(s):  
Javier A Neyra ◽  
Orson W Moe ◽  
Johanne Pastor ◽  
Fabiola Gianella ◽  
Sachdev S Sidhu ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Protease Inhibitor ◽  
Human Serum ◽  
Kidney Function ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Freeze Thaw ◽  
Human Serum Samples ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle

Abstract Background Soluble Klotho has multiple systemic salutary effects. In animals, both acute and chronic kidney disease models display systemic Klotho deficiency. As such, there is considerable interest in investigating soluble Klotho as a biomarker in patients with different types and severity of kidney diseases. Unfortunately, there remains uncertainty regarding the best method to measure soluble Klotho in human serum samples. Methods Using human serum samples obtained from several clinical cohorts with a wide range of kidney function, we measured soluble Klotho using a commercial enzyme-linked immunosorbent assay (ELISA) as well as with an immunoprecipitation–immunoblot (IP–IB) assay utilizing a synthetic antibody with high affinity and specificity for Klotho. Recovery of spiking with a known amount of exogenous Klotho was tested. A subset of samples was analyzed with and without the addition of a protease inhibitor cocktail at the time of collection or after the first freeze–thaw cycle to determine if these maneuvers influenced performance. Results The IP–IB assay was superior to the ELISA at recovery of exogenous Klotho (81–115% versus 60–81%) across the spectrum of kidney function. Klotho measurements by IP–IB were highly correlated with estimated glomerular filtration rate (eGFR) (R = 0.80, P < 0.001) in comparison with the commercial ELISA, which exhibited minimal correlation with eGFR (R = 0.18, P = 0.12). Use of a protease inhibitor cocktail neither improved nor impaired performance of the IP–IB assay; however, subsequent freeze–thaw cycle resulted in a significant reduction in Klotho recovery and dissipated the correlation between Klotho levels and eGFR. With the ELISA, the use of protease inhibitor cocktail resulted in an increase in intrasubject variability. Conclusions The IP–IB assay is preferable to the commercial ELISA to measure soluble Klotho concentrations in never-thawed serum samples of humans with varying severity of kidney disease. However, due to the labor-intensive nature of the IP–IB assay, further research is needed to secure an assay suitable for high-throughput work.

scholarly journals Strength and Microscopic Damage Mechanism of Yellow Sandstone with Holes under Freezing and Thawing

2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Huren Rong ◽  
Jingyu Gu ◽  
Miren Rong ◽  
Hong Liu ◽  
Jiayao Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Pore Size ◽  
Power Function ◽  
Damage Mechanism ◽  
Uniaxial Compression Test ◽  
Freezing And Thawing ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Microscopic Damage

In order to study the damage characteristics of the yellow sandstone containing pores under the freeze-thaw cycle, the uniaxial compression test of saturated water-stained yellow sandstones with different freeze-thaw cycles was carried out by rock servo press, the microstructure was qualitatively analyzed by Zeiss 508 stereo microscope, and the microdamage mechanism was quantitatively studied by using specific surface area and pore size analyzer. The mechanism of weakening mechanical properties of single-hole yellow sandstone was expounded from the perspective of microstructure. The results show the following. (1) The number of freeze-thaw cycles and single-pore diameter have significant effects on the strength and elastic modulus of the yellow sandstone; the more the freeze-thaw cycles and the larger the pore size, the lower the strength of the yellow sandstone. (2) The damage modes of the yellow sandstone containing pores under the freeze-thaw cycle are divided into five types, and the yellow sandstone with pores is divided into two areas: the periphery of the hole and the distance from the hole; as the number of freeze-thaw cycles increases, different regions show different microscopic damage patterns. (3) The damage degree of yellow sandstone is different with freeze-thaw cycle and pore size. Freeze-thaw not only affects the mechanical properties of yellow sandstone but also accelerates the damage process of pores. (4) The damage of the yellow sandstone by freeze-thaw is logarithmic function, and the damage of the yellow sandstone is a power function. The damage equation of the yellow sandstone with pores under the freezing and thawing is a log-power function nonlinear change law and presents a good correlation.

scholarly journals USING SMOS PASSIVE MICROWAVE DATA TO DEVELOP SMAP FREEZE/THAW ALGORITHMS ADAPTED FOR THE CANADIAN SUBARCTIC

2015 ◽  
Vol XL-1-W5 ◽  
pp. 365-368 ◽  
Author(s):  
P. Kalantari ◽  
M. Bernier ◽  
K. C. McDonal ◽  
J. Poulin
Keyword(s):  
Land Cover ◽  
Time Series Data ◽  
Passive Microwave ◽  
Soil Freezing ◽  
Series Data ◽  
Freezing And Thawing ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
The Impact

Seasonal terrestrial Freeze/Thaw cycle in Northern Quebec Tundra (Nunavik) was determined and evaluated with passive microwave observations. SMOS time series data were analyzed to examine seasonal variations of soil freezing, and to assess the impact of land cover on the Freeze/Thaw cycle. Furthermore, the soil freezing maps derived from SMOS observations were compared to field survey data in the region near Umiujaq. The objective is to develop algorithms to follow the seasonal cycle of freezing and thawing of the soil adapted to Canadian subarctic, a territory with a high complexity of land cover (vegetation, soil, and water bodies). Field data shows that soil freezing and thawing dates vary much spatially at the local scale in the Boreal Forest and the Tundra. The results showed a satisfactory pixel by pixel mapping for the daily soil state monitoring with a > 80% success rate with in situ data for the HH and VV polarizations, and for different land cover. The average accuracies are 80% and 84% for the soil freeze period, and soil thaw period respectively. The comparison is limited because of the small number of validation pixels.

scholarly journals Mechanical Properties of Sandstone Cement-Stabilized Macadam

2019 ◽  
Vol 9 (17) ◽  
pp. 3460 ◽  
Author(s):  
Qiang Du ◽  
Ting Pan ◽  
Jing Lv ◽  
Jie Zhou ◽  
Qingwei Ma ◽  
...  
Keyword(s):  
Cement Content ◽  
Influence Factors ◽  
Road Construction ◽  
Experimental Investigations ◽  
Freezing And Thawing ◽  
Freeze Thaw ◽  
Test Pieces ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Brazilian Splitting

Application of sandstone in cement-stabilized macadam (CSM) is an effective way to utilize sandstone. To determine the feasibility of using sandstone as a CSM aggregate, a series of experimental investigations, such as unconfined compressive strength (UCS) tests, Brazilian splitting tests and freeze-thaw cycle tests, were conducted on sandstone cement-stabilized macadam (SCSM). Three mixed variables, covering the cement content, aggregate type and curing period, were set as influence factors. The testing results indicated that the UCS, indirect tensile strength (ITS) and frost resistance property of the test-pieces increased with cement content and curing age. Considering the asphalt pavement design specifications for China, the UCS and ITS values of the SCSM complied with the requirements of light traffic road construction before freeze-thaw cycles. However, the SCSM subjected to freezing and thawing meets the requirements only when the cement content is 4.5%. Therefore, it is noteworthy that CSM containing sandstone aggregates should be applied with caution in cold region because of insufficient freeze resistance.

scholarly journals The Effects of a Single Freeze-Thaw Cycle on Concentrations of Nutritional, Noncommunicable Disease, and Inflammatory Biomarkers in Serum Samples

2021 ◽  
Author(s):  
Ransi Ann Abraham ◽  
Garima Rana ◽  
Praween K. Agrawal ◽  
Robert Johnston ◽  
Avina Sarna ◽  
...  
Keyword(s):  
Large Scale ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Noncommunicable Disease ◽  
Noncommunicable Diseases ◽  
Serum Samples ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
The Stability

Abstract Background The stability of biological samples is vital for reliable measurements of biomarkers in large-scale survey settings, which may be affected by freeze-thaw procedures. We examined the effect of a single freeze-thaw cycle on 13 nutritional, noncommunicable diseases (NCD), and inflammatory bioanalytes in serum samples. Method Blood samples were collected from 70 subjects centrifuged after 30 minutes and aliquoted immediately. After a baseline analysis of the analytes, the samples were stored at − 70°C for 1 month and reanalyzed for all the parameters. Mean percentage differences between baseline (fresh blood) and freeze-thaw concentrations were calculated using paired sample t-tests and evaluated according to total allowable error (TEa) limits (desirable bias). Results Freeze-thaw concentrations differed significantly (p < 0.05) from baseline concentrations for soluble transferrin receptor (sTfR) (− 5.49%), vitamin D (− 12.51%), vitamin B12 (− 3.74%), plasma glucose (1.93%), C-reactive protein (CRP) (3.45%), high-density lipoprotein (HDL) (7.98%), and cholesterol (9.76%), but they were within respective TEa limits. Low-density lipoprotein (LDL) (− 0.67%), creatinine (0.94%), albumin (0.87%), total protein (1.00%), ferritin (− 0.58%), and triglycerides (TAG) (2.82%) concentrations remained stable following the freeze-thaw cycle. In conclusion, single freeze-thaw cycle of the biomarkers in serum/plasma samples after storage at − 70°C for 1 month had minimal effect on stability of the studied analytes, and the changes in concentration were within acceptable limit for all analytes.

Phenotyping of Hyperlipoproteinemias

1970 ◽  
Vol 16 (6) ◽  
pp. 507-511 ◽  
Author(s):  
James Winkelman ◽  
Donald R Wybenga ◽  
Frank A Ibbott
Keyword(s):  
Cellulose Acetate ◽  
Room Temperature ◽  
Cellulose Acetate Electrophoresis ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
The Stability

Abstract The stability of serum specimens collected for cellulose acetate electrophoresis of lipoproteins has been studied for each of the hyperlipoproteinemia phenotypes. In general, samples kept at room temperature for three days are still suitable for analysis. On longer standing, artifacts can cause misinterpretation of strips, or render them completely unreadable. If specimens are stored at refrigerator or freezer temperatures, deterioration is retarded but the period of stability after they are returned to room temperature is unaltered. A second freeze-thaw cycle makes specimens unsuitable for analysis. Samples can be stored at refrigerator temperatures for at least 28 days and at freezer temperatures for at least 14 days if one freeze-thaw cycle is used.

scholarly journals PSXIII-2 Cryopreservation effect on biological parameters of poultry semen

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 372-373
Author(s):  
Mikhail A Zhilinsky ◽  
Evgeniya K Tomgorova ◽  
Baylar S Iolchiev ◽  
Anastasia N Vetokh ◽  
Hanum V Ashraf ◽  
...  
Keyword(s):  
Germ Cells ◽  
Genetic Material ◽  
Middle Section ◽  
Sperm Cryopreservation ◽  
Freezing And Thawing ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Negative Effect ◽  
Live Sperm

Abstract Sperm cryopreservation is one of the most important elements for the creation of genetic material cryobanks in order to preserve the gene pool of poultry. Cryopreservation methods and parameters directly affect the viability of germ cells after thawing. The effect of freeze-thaw cycles on biological usefulness of bird sperm was studied. Semen was frozen in paillettes. Thawing sperm was carried out at a temperature of 38 °С. Sperm activity was assessed using CASA technology “ARGUSSOFT”. Sperm motility after cryopreservation decreased in roosters, quails and guinea fowls by 62 ± 3 %, 66 ± 1 % and 60 ± 1 %, respectively. The proportion of live sperm also decreased: in roosters - from 89 ± 4 % to 48 ± 2 %, in quails - from 93 ± 3 % to 49 ± 3 %, in the guinea fowls - from 92 ± 2 % to 45 ± 4 %. As a result of freezing and thawing, the proportion of spermatozoa with abnormal morphology increased. A change in the frequency of anomalies occurrence in individual segments was observed. The number of spermatozoa with flagella pathology was increased. The proportion of sperm with pathology of the head, middle section and flagellum increased by 0.4 %, 0.4 % and 1.3 % (P ≤ 0.001) respectively, in the frozen-thawed samples of roosters, compared with the indicators established for a freshly obtained ejaculate. A similar trend was observed in other poultry types. Thus, the freeze-thaw cycle had a negative effect on the activity and viability of poultry spermatozoa. Supported by RSF No 16-16-04104.

Laboratory Test of Uniaxial Compressive Strength of Shanghai Frozen Soils under Freeze-Thaw Cycle

2013 ◽  
Vol 716 ◽  
pp. 688-692 ◽  
Author(s):  
Xiang Dong Hu ◽  
Jin Tai Wang ◽  
Xing Fu Yu
Keyword(s):  
Soft Soil ◽  
Underground Space ◽  
Freezing And Thawing ◽  
Frozen Soils ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Ground Freezing ◽  
Freeze Thaw Cycle ◽  
Artificial Ground Freezing ◽  
Mechanical Characters

The artificial ground freezing (AGF) is now widely employed in constructions with the expanding underground space exploitation in Shanghai. In order to avoid geological disasters which might appear in the AGF practice, it is urgently needed to do laboratory tests on the physical and mechanical characters of Shanghai soft soil under freezing and thawing action. This paper tests three kinds of soils from the location ofShanghai Metro line 4 constructions in different state, i.e. original state, freeze-thaw state and secondary freeze-thaw state, and obtains the changing rules of soil characters under secondary freeze-thaw action.

scholarly journals Numerical Simulation of the Effect of Freeze–Thaw Cycles on the Durability of Concrete in a Salt Frost Environment

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1198
Author(s):  
Hao Li ◽  
Yuan Zhang ◽  
Haolong Guo
Keyword(s):  
Numerical Simulation ◽  
Bending Moment ◽  
Temperature Curve ◽  
Concrete Durability ◽  
Freezing And Thawing ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
The Impact ◽  
Erosion Environment

In order to improve the accuracy of the analysis of the impact of freeze–thaw cycle on concrete durability in a salt freezing environment, the numerical simulation of the impact of the freeze–thaw cycle on concrete durability in a salt freezing erosion environment is studied in this paper. Firstly, considering the influence of axial force and bending moment on the relationship between bending moment and curvature, a concrete fiber beam column model is established. Then, according to the joint influence of temperature field, stress field and seepage field on concrete in the process of freezing and thawing, the control differential equation of the freezing and thawing cycle is established. The freeze–thaw damage section is divided, the non-uniform distribution of freeze–thaw damage is determined, and the division of the freeze–thaw damage section is completed. According to the linear relationship between freeze–thaw damage degree, relative dynamic elastic modulus, freeze–thaw cycle times and position variables, the durability of concrete is numerically simulated, and the attenuation law of bond strength at different section depths after freeze–thaw is determined. The results show that the temperature curve simulated by the design method is consistent with the actually measured temperature curve, which can better reduce the temperature change of the inner core of the test block during freezing and thawing, and the relative dynamic elastic modulus is in good agreement with the actual value, which can prove that the method in this paper has certain practical application value. It is expected to provide some reference for solving the durability problem of concrete in a salt frost erosion environment and the optimal design of concrete structures.

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