Effects of Serum Stored at Various Temperature and FreezeThaw Cycles on Selected Biochemical Parameters

Introduction: Preanalytical variation as a result of sample storage conditions are common issues in a large scale study since the sample has to be kept for an extended duration at ultra low temperature (-70ºC) before analysis. However, ultra low freezers may not be available in some laboratories. Sometimes, the laboratory test may need to be repeated on the previously frozen and thawed samples. The aim of this research was to study the effect of storage temperature and freeze-thaw cycles on some biochemical parameters in our laboratory. Methods: An experimental study was carried out on 50 volunteers. Serum were aliquoted and stored at 4ºC, -30ºC and -70ºC. The serum was analyzed for total cholesterol (TC), triglycerides (TG), high density-lipoprotein (HDL-C) and glucose after 3 months of storage. The effects of freeze-thaw cycles were also recorded. Results: No significant differences (p>0.05) were seen in the level of the biochemical parameters between the samples stored at -70ºC and at -30ºC. The levels of selected parameters were higher after second freeze-thaw cycles as compared to the first thaw. All parameters showed significant positive correlations between the samples stored at -70ºC and the samples stored at -30ºC and 4ºC as well as between the first and second freeze-thaw cycles in samples kept at both -70ºC and -30ºC. Conclusions: Our finding suggested that the level of TC, TG and glucose in sample stored for 3 months at -70ºC are comparable with the samples stored at -30ºC. Only one freeze-thaw cycle is acceptable.

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Effects of Processing and Storage Conditions on Amyloid β (1–42) and Tau Concentrations in Cerebrospinal Fluid: Implications for Use in Clinical Practice

Clinical Chemistry ◽

10.1373/clinchem.2004.039735 ◽

2005 ◽

Vol 51 (1) ◽

pp. 189-195 ◽

Cited By ~ 102

Author(s):

Niki SM Schoonenboom ◽

Cees Mulder ◽

Hugo Vanderstichele ◽

Evert-Jan Van Elk ◽

Astrid Kok ◽

...

Keyword(s):

Cerebrospinal Fluid ◽

Storage Temperature ◽

Amyloid Β ◽

Quantitative Result ◽

Storage Conditions ◽

Freeze Thaw ◽

Thaw Cycle ◽

Freeze Thaw Cycle ◽

Processing And Storage ◽

And Storage

Abstract Background: Reported concentrations of amyloid β (1–42) (Aβ42) and tau in cerebrospinal fluid (CSF) differ among reports. We investigated the effects of storage temperature, repeated freeze/thaw cycles, and centrifugation on the concentrations of Aβ42 and tau in CSF. Methods: Stability of samples stored at −80 °C was determined by use of an accelerated stability testing protocol according to the Arrhenius equation. Aβ42 and tau concentrations were measured in CSF samples stored at 4, 18, 37, and −80 °C. Relative CSF concentrations (%) of the biomarkers after one freeze/thaw cycle were compared with those after two, three, four, five, and six freeze/thaw cycles. In addition, relative Aβ42 and tau concentrations in samples not centrifuged were compared with samples centrifuged after 1, 4, 48, and 72 h. Results: Aβ42 and tau concentrations were stable in CSF when stored for a long period at −80 °C. CSF Aβ42 decreased by 20% during the first 2 days at 4, 18, and 37 °C compared with −80 °C. CSF tau decreased after storage for 12 days at 37 °C. After three freeze/thaw cycles, CSF Aβ42 decreased 20%. CSF tau was stable during six freeze/thaw cycles. Centrifugation did not influence the biomarker concentrations. Conclusions: Repeated freeze/thaw cycles and storage at 4, 18, and 37 °C influence the quantitative result of the Aβ42 test. Preferably, samples should be stored at −80 °C immediately after collection.

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

Journal of Laboratory Physicians ◽

10.1055/s-0041-1726575 ◽

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.

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The effects of a freeze-thaw cycle and pre-analytical storage temperature on the stability of insulin-like growth factor-I and pro-collagen type III N-terminal propeptide concentrations: Implications for the detection of growth hormone misuse in athletes

Drug Testing and Analysis ◽

10.1002/dta.1339 ◽

2012 ◽

Vol 4 (6) ◽

pp. 455-459 ◽

Cited By ~ 7

Author(s):

Nishan Guha ◽

Ioulietta Erotokritou-Mulligan ◽

Christiaan Bartlett ◽

David A. Cowan ◽

E. Eryl Bassett ◽

...

Keyword(s):

Growth Hormone ◽

Growth Factor ◽

Collagen Type ◽

Storage Temperature ◽

Collagen Type Iii ◽

Freeze Thaw ◽

Factor I ◽

Thaw Cycle ◽

Freeze Thaw Cycle ◽

The Stability

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Experimental investigation on combined modification for micro physicochemical characteristics of coal by compound reagents and liquid nitrogen freeze-thaw cycle

Fuel ◽

10.1016/j.fuel.2021.120287 ◽

2021 ◽

Vol 292 ◽

pp. 120287

Author(s):

Weibo Han ◽

Gang Zhou ◽

Junpeng Wang ◽

Wenjing Jiang ◽

Qian Zhang ◽

...

Keyword(s):

Experimental Investigation ◽

Liquid Nitrogen ◽

Physicochemical Characteristics ◽

Freeze Thaw ◽

Thaw Cycle ◽

Freeze Thaw Cycle

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The effect of freeze–thaw cycle on the low-temperature properties of asphalt fine aggregate matrix utilizing bending beam rheometer

Cold Regions Science and Technology ◽

10.1016/j.coldregions.2016.02.008 ◽

2016 ◽

Vol 125 ◽

pp. 101-107 ◽

Cited By ~ 20

Author(s):

Xiangbing Gong ◽

Pedro Romero ◽

Zejiao Dong ◽

Daniel Scott Sudbury

Keyword(s):

Low Temperature ◽

Fine Aggregate ◽

Bending Beam Rheometer ◽

Freeze Thaw ◽

Thaw Cycle ◽

Freeze Thaw Cycle ◽

Fine Aggregate Matrix

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Effect of freeze–thaw cycle on physical and mechanical properties and damage characteristics of sandstone

Scientific Reports ◽

10.1038/s41598-021-91842-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Longxiao Chen ◽

Kesheng Li ◽

Guilei Song ◽

Deng Zhang ◽

Chuanxiao Liu

Keyword(s):

Mechanical Properties ◽

Shear Failure ◽

Triaxial Compression ◽

Physical And Mechanical Properties ◽

Freeze Thaw ◽

Damage Characteristics ◽

Large Pore ◽

Natural Rock ◽

Thaw Cycle ◽

Freeze Thaw Cycle

AbstractRock deterioration under freeze–thaw cycles is a concern for in-service tunnel in cold regions. Previous studies focused on the change of rock mechanical properties under unidirectional stress, but the natural rock mass is under three dimensional stresses. This paper investigates influences of the number of freeze–thaw cycle on sandstone under low confining pressure. Twelve sandstone samples were tested subjected to triaxial compression. Additionally, the damage characteristics of sandstone internal microstructure were obtained by using acoustic emission (AE) and mercury intrusion porosimetry. Results indicated that the mechanical properties of sandstone were significantly reduced by freeze–thaw effect. Sandstone’ peak strength and elastic modulus were 7.28–37.96% and 6.38–40.87% less than for the control, respectively. The proportion of super-large pore and large pore in sandstone increased by 19.53–81.19%. We attributed the reduced sandstone’ mechanical properties to the degenerated sandstone microstructure, which, in turn, was associated with increased sandstone macropores. The macroscopic failure pattern of sandstone changed from splitting failure to shear failure with an increasing of freeze–thaw cycles. Moreover, the activity of AE signal increased at each stage, and the cumulative ringing count also showed upward trend with the increase of freeze–thaw number.

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Non-linear creep damage model of sandstone under freeze-thaw cycle

Journal of Central South University ◽

10.1007/s11771-021-4656-3 ◽

2021 ◽

Vol 28 (3) ◽

pp. 954-967

Author(s):

Jie-lin Li ◽

Long-yin Zhu ◽

Ke-ping Zhou ◽

Hui Chen ◽

Le Gao ◽

...

Keyword(s):

Damage Model ◽

Creep Damage ◽

Freeze Thaw ◽

Thaw Cycle ◽

Linear Creep ◽

Non Linear ◽

Freeze Thaw Cycle ◽

Creep Damage Model

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

Advances in Civil Engineering ◽

10.1155/2020/5921901 ◽

2020 ◽

Vol 2020 ◽

pp. 1-13 ◽

Cited By ~ 1

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.

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Studies the Properties of Polyaspartic Polyurea Coated Concrete under Coaction of Salt Fog and Freeze-Thaw

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.455-456.781 ◽

2012 ◽

Vol 455-456 ◽

pp. 781-785

Author(s):

Ping Lu ◽

Xin Mao Li ◽

Xue Qiang Ma ◽

Wei Bo Huang

Keyword(s):

Elastic Modulus ◽

Frost Resistance ◽

Dynamic Elastic Modulus ◽

Freeze Thaw ◽

Decrease Rate ◽

Thaw Cycle ◽

Freeze Thaw Cycle ◽

Salt Fog

. This paper mainly studied the properties of PAE polyurea coated concrete under coactions of salt fog and freeze-thaw. After exposed salt fog conditions for 200d, T3, B2, F2 and TM four coated concrete relative dynamic elastic modulus have small changes, but different coated concrete variation amplitude is different. T3 coated concrete after 100 times of freeze-thaw cycle the relative dynamic elastic modulus began to drop, 200 times freeze-thaw cycle ends, relative dynamic elastic modulus variation is the largest, decrease rate is 95%, TM concrete during 200 times freeze-thaw cycle, relative dynamic elastic modulus almost no change, B2 concrete and F2 concrete the extent of change between coating T3 and TM. After 300 times the freeze-thaw cycle coated concrete didn't appear freeze-thaw damage phenomenon. Four kinds of coating concrete relative dynamic elastic modulus variation by large to small order: T3 coated concrete > B2 coated concrete >F2 coated concrete > TM coated concrete, concrete with the same 200d rule. Frost resistance order, by contrast, TM coated concrete > B2 coated concrete > F2 coated concrete > T3 coated concrete.

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