Effect of duration and temperature of storage on serum analyte stability: examination of 14 selected radioimmunoassay procedures.

1982 ◽  
Vol 28 (1) ◽  
pp. 164-165 ◽  
Author(s):  
N P Kubasik ◽  
M Ricotta ◽  
T Hunter ◽  
H E Sine

Abstract We determined appropriate temperatures for sample storage and the resulting stability of 14 analytes commonly radioimmunoassayed in the clinical laboratory. Serum specimens to be tested for concentrations of cholylglycine, cortisol, digoxin, ferritin, follitropin, immunoglobulin E, lutropin, prolactin, thyroxin (also blood-spot thyroxin), triiodothyronine, and triiodothyronine uptake could be stored for up to two weeks at room temperature, refrigerated, or frozen without any loss of analyte activity. Specimens for insulin testing require freezing or refrigeration, and specimens for gastrin testing should be stored at -70 degrees C for optimal results.

Author(s):  
M. Quan ◽  
M.S. Mulders ◽  
D.G.A. Meltzer

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.


Author(s):  
Nick Verougstraete ◽  
Bruno Lapauw ◽  
Sara Van Aken ◽  
Joris Delanghe ◽  
Christophe Stove ◽  
...  

AbstractBackground:Microsampling techniques have several advantages over traditional blood collection. Dried blood spot (DBS) sampling and blood collection with heparinized capillaries are the standard techniques. Volumetric absorptive microsampling (VAMS) is a novel technique that collects a fixed volume of blood by applying an absorbent tip to a blood drop. In the present study we explored the feasibility of HbAMethods:Diabetic patients were enrolled in this study during consultation with the endocrinologist. A venous (adults) or capillary (children) sample was taken for immediate HbAResults:The median time between sampling at home and analysis was 3 days. Results of HbAConclusions:Utilizing equipment standard available in the clinical laboratory, the use of home-sampled dried VAMS and DBS is not a reliable tool for the monitoring of HbA


Author(s):  
Gilang Nugraha ◽  
Nur Anita Ningsih ◽  
Titik Sulifah ◽  
Sitti Fitria

Complete blood count (CBC) is one of the laboratory tests most often influenced by doctors. The use of a hematology analyzer offers a wider range of probe parameters. The pre-analytic stage accounts for 70% of errors, one of which is the delay of the examination. Changes in report results were reported due to changes in blood cell morphology due to EDTA additives and room temperature. The aim of this research is the disturbance of stability of the results of examination of various CBC parameters in blood samples that are left at room temperature for 24 hours using a hematology analyzer. This experimental laboratory research was conducted at the Pramita Jemur Andayani Clinical Laboratory. Blood samples were obtained from volunteers, stored at room temperature and subjected to immediate examination (control) and after a delay of 6, 12 and 24 hours (treatment). A total of 30 respondents, consisting of 8 men and 22 women. The mean age of the respondents was 22 ± 1 year. There was no difference in the results of the examination (p-value > 0.05) in the RBC, Hct MCV, MCHC, PLT and PDW. The results of the examination (p-value < 0.05) were found on Hgb, MCH, RDW, WBC, NEU, IG, MONO, EO, BASO, LYM, PLT and PDW. Delayed CBC examinations using the CELL-DYN Ruby hematology analyzer directly gave different results on several parameters ranging from 6 hours delay of examination.


Metabolites ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 515
Author(s):  
Daniela Duarte ◽  
Beatriz Castro ◽  
Joana Leonor Pereira ◽  
Joana Faria Marques ◽  
Ana Luísa Costa ◽  
...  

Maintaining a salivary metabolic profile upon sample collection and preparation is determinant in metabolomics. Nuclear magnetic resonance (NMR) spectroscopy was used to identify metabolite changes during short-term storage, at room temperature (RT)/4 °C/−20 °C, and after sample preparation, at RT/4 °C (mimicking typical clinical/laboratory settings). Interestingly, significant metabolic inter-individual and inter-day variability were noted, probably determining sample stability to some extent. After collection, no changes were noted at −20 °C (at least for 4 weeks). RT storage induced decreases in methylated macromolecules (6 h); lactate (8 h); alanine (12 h); galactose, hypoxanthine, pyruvate (24 h); sarcosine, betaine, choline, N-acetyl-glycoproteins (48 h), while acetate increased (48 h). Less, but different, changes were observed at 4 °C, suggesting different oral and microbial status at different temperatures (with a possible contribution from inter-individual and inter-day variability), and identifying galactose, hypoxanthine, and possibly, choline esters, as potential general stability indicators. After preparation, addition of NaN3 did not impact significantly on saliva stabilization, neither at RT nor at 4 °C, although its absence was accompanied by slight increases in fucose (6.5 h) and proline (8 h) at RT, and in xylose (24 h) at 4 °C. The putative metabolic origins of the above variations are discussed, with basis on the salivary microbiome. In summary, after collection, saliva can be stored at RT/4 °C for up to 6 h and at −20 °C for at least 4 weeks. Upon preparation for NMR analysis, samples are highly stable at 25 °C up to 8 h and at 4 °C up to 48 h, with NaN3 addition preventing possible early changes in fucose, proline (6–8 h), and xylose (24 h) levels.


Medicina ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 54-74
Author(s):  
A. S. Shulga ◽  
◽  
N. N. Kraynova ◽  
D. V. Burtsev ◽  
◽  
...  

Sample stability is essential for reliable results in clinical laboratory practice. The aim of the work was to investigate the change in values of hematological indices in samples stored for up to 72 hours under different temperature regimes. A total of 60 whole blood samples stored under different conditions were analyzed: at room temperature (25°C), heated to 35°C and cooled to 4°C. Analysis was performed at different time points: immediately after blood sampling and then consecutively after 3, 6, 12, 24, 48 and 72 hours. K2EDTA anticoagulant tubes were used, and results were obtained using a UniCel DxH 800 hematology analyzer. The median shift of the parameters relative to baseline for each combination of time and temperature was assessed using the Wilcoxon matched pairs test. The shift in hemogram values obtained using Bland-Altman plots was compared with the maximum permissible error specified in the quality specification for the desirable error. Hemoglobin, erythrocyte count, mean erythrocyte hemoglobin content and platelet content were stable for at least 72 hours at all temperatures used in the experiment. For the other tested parameters, the first unacceptable changes in hemogram values were observed after 3 hours when the samples were stored at 25°C and 35°C. In samples cooled to 4°C, the first statistically significant differences were recorded after 6 hours. As a result, storage of samples for 72 hours at room temperature led to reliable unacceptable changes in 6 hemogram parameters of the 11 studied, at 4°C 5 parameters changed unacceptably, and at 35°C – 7 parameters. The obtained results, on the one hand, indicate that when analyzing the results of hematological tests is performed with a delay after sample collection, changes in hematological parameters should be considered; on the other hand, they provide information about the list of parameters subject to temperature-time changes, as well as about the intensity of these changes.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4063-4063
Author(s):  
Roger C Munro ◽  
Jeremy Tranter ◽  
Laura Hart ◽  
Ruth Jones ◽  
Ann Benton ◽  
...  

Abstract Introduction: Processing blood samples for full blood count may be delayed for a multitude of reasons. There is little published information on the effect of sample storage on platelet count. This study compares the effect of storing normal samples at room temperature (RT) and at 4°C prior to processing using different analysers with different technologies. Sysmex SF 3000 and XE2100 analysers are capable of providing impedance (IMP) platelet counts and the latter can also perform fluorescence based optical (OPT) platelet counts. The Coulter LH750 and the ABX Pentra DX120 use IMP technology with enhanced data extraction techniques and algorithms to eliminate interference. Method: Intravenous blood samples for routine blood counts were taken into 4ml K2 EDTA Greiner Vacuette containers from 20 out-patients and the platelet counts measured at 0, 6 and 24 hrs on Coulter LH750 (IMP), ABX Pentra DX120 (IMP), Sysmex SF3000 (IMP) and Sysmex XE2100 (both IMP and OPT) blood count analysers. Samples were stored at RT. Samples were also processed on the XE2100 following storage at 4°C. Results: Mean changes in platelet counts (n = 20) expressed as percentages of the original value at 0 hrs and paired t-test values of significance are shown in the Table. The most significant changes occurred with the XE2100 where the IMP value increased by 7% over 24 hrs but the OPT value fell by 5%. No significant changes occurred with the Coulter or the ABX analysers at 0 and 24 hrs or with the SF3000 at 6 hrs. 6 hr v 0 hr 24 hr v 0 hr % change p % change p Coulter RT + 0.19 0.873 −0.12 0.908 ABX Pentra DX120 RT + 0.02 0.985 + 0.57 0.380 SF 3000 RT + 1.25 0.281 + 2.52 &lt;0.05 XE 2100 Imp RT + 5.26 &lt;.05 + 7.06 &lt;0.05 XE 2100 Imp 4°C + 3.31 &lt;0.05 + 5.06 &lt;0.05 XE 2100 Opt RT −2.20 &lt;0.0 −5.32 &lt;0.05 XE 2100 Opt 4°C + 2.30 &lt;0.05 −0.40 0.750 EDTA exposure and the formation of membrane lesions during sample storage leads to changes in platelet structure, volume, function and shape due to decreased optical density and the beginning of degranulation. All these have a potential impact on the accurate assessment of platelet numbers. If these numbers are to be used accurately as thresholds for platelet transfusion or for monitoring progressive loss or increases of platelets associated with underlying pathology, it is vital that the pre-analytical limitations of current analysers are fully understood. The way in which discriminators are used on various analysers to make distinction between the characteristics of platelets and other blood cells in individual, stored samples will vary in their effectiveness. Conclusions: Our data indicate that various combinations of pre-analytical sample storage and analyser technology should be considered as potential influences on the outcome of platelet counting in the clinical laboratory.


2001 ◽  
Vol 689 ◽  
Author(s):  
Li Yang ◽  
J. M. Vieira ◽  
Kaibin Tang ◽  
Guien Zhou

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.


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