Stability of 5-fluorouracil in whole blood and plasma.

1987 ◽  
Vol 33 (12) ◽  
pp. 2299-2300 ◽  
Author(s):  
R F Murphy ◽  
F M Balis ◽  
D G Poplack

Abstract We studied the stability of 5-fluorouracil (5-FU) in plasma and whole blood kept at room temperature and on ice for 1 to 24 h. At room temperature, there was a steady loss of 94% of the parent drug over 24 h in whole blood and 52% in plasma. In the presence of an excess of uracil, 5-FU was stable for 24 h, suggesting that the loss of 5-FU is the result of enzymatic degradation. 5-FU is more stable in whole blood and plasma when samples are kept cold. For blood and plasma samples maintained on ice, the loss was only 30% and 10% of the parent drug in the respective samples over 24 h. Frozen plasma samples (-20 degrees C) were stable for five weeks. Blood specimens collected for quantifying 5-FU should be immediately placed on ice, and the plasma should be separated and frozen as promptly as possible.

2020 ◽  
pp. 193229682096365
Author(s):  
Stefan Pleus ◽  
Guido Freckmann ◽  
Annette Baumstark ◽  
Cornelia Haug

Background: Conflicting information is available regarding the stability of glucose concentrations in frozen plasma samples. Clinical trials could benefit from such long-term storage because it would allow usage of a central laboratory with higher-quality laboratory analyzers in contrast to mobile analyzers in a decentralized setting. Methods: In this study, venous blood samples were collected in lithium-heparin gel tubes. Plasma was separated immediately after blood was drawn, and from each of the 21 plasma samples, 6 aliquots were prepared for measurement at 6 time points: immediately and after 2, 4, 6, 8, and 12 weeks. Between sampling and measurement, aliquots were stored at less than −20°C. Transport on dry ice was simulated by placing aliquots in a −80°C freezer for 5 days between weeks 8 and 12. Measurements were performed on a hexokinase-based laboratory analyzer. Average relative differences and corresponding 99% confidence intervals (CIs) were calculated between the stored aliquots’ and the immediately measured aliquots’ glucose concentrations. Glucose concentrations were deemed stable as long as average relative differences were ≤±2.5%. Results: Over the whole 12-weeks duration, the largest average relative difference was −1.82% (99% CI: –2.25% to −1.39%). Shorter storage durations tended to lead to less bias. Conclusion: In this study, the stability of glucose concentrations in frozen plasma samples obtained with lithium-heparin gel tubes could be shown for up to 12 weeks. Future studies should be performed to assess whether this is independent of the glucose analyzer and the type of sampling tube used.


1989 ◽  
Vol 35 (12) ◽  
pp. 2313-2316 ◽  
Author(s):  
S E Hankinson ◽  
S J London ◽  
C G Chute ◽  
R L Barbieri ◽  
L Jones ◽  
...  

Abstract We examined the stability of lipids, carotenoids, alpha-tocopherol, and endogenous hormones in plasma prepared from whole blood that had been mailed to a central location for processing. Initially, to simulate transport conditions, whole-blood samples were stored in the laboratory, either at room temperature or cooled, for up to 72 h before processing. In the latter samples, lipid concentrations changed up to 1.4% per day, carotenoids up to -5.5%, and hormones up to 9.5%. In a second study, analyte concentrations in plasma from cooled whole blood mailed via overnight courier were compared with those from plasma that had been immediately separated, frozen, and mailed via overnight courier. Concentrations of cholesterol, high-density lipoprotein subfraction 3, apolipoprotein B, and retinol were stable. Overall, for each marker except estradiol, the between-person variation was at least twice the within-person variation. In a third study, at least 340 micrograms of DNA was recovered from 30 mL of cool-shipped whole blood. Our results indicate that shipping whole-blood samples by overnight courier is feasible for assay of several biochemical markers of interest in epidemiological research.


2018 ◽  
Vol 62 (9) ◽  
Author(s):  
Ronilda D'Cunha ◽  
Thanh Bach ◽  
Beth Ann Young ◽  
Peizhi Li ◽  
Demet Nalbant ◽  
...  

ABSTRACT Although the stability of β-lactam antibiotics is a known issue, none of the previously reported bioanalytical methods had an adequate evaluation of the stability of these drugs. In the current study, the stability of cefepime, meropenem, piperacillin, and tazobactam under various conditions was comprehensively evaluated. The evaluated parameters included stock solution stability, short-term stability, long-term stability, freeze-thaw stability, processed sample stability, and whole-blood stability. When stored at −20°C, the stock solution of meropenem in methanol was stable for up to 3 weeks, and the stock solutions of cefepime, piperacillin, and tazobactam were stable for up to 6 weeks. All four antibiotics were stable in human plasma for up to 3 months when stored at −80°C and were stable in whole blood for up to 4 h at room temperature. Short-term stability results indicated that all four β-lactams were stable at room temperature for 2 h, but substantial degradation was observed when the plasma samples were stored at room temperature for 24 h, with the degradation rates for cefepime, meropenem, piperacillin, and tazobactam being 30.1%, 75.6%, 49.0%, and 37.7%, respectively. Because the stability information is method independent, our stability results can be used as a reference by other research groups that work with these antibiotics.


2009 ◽  
Vol 11 (4) ◽  
pp. 395-400 ◽  
Author(s):  
Tai-Chu Peng ◽  
Bang-Gee Hsu ◽  
Fwu-Lin Yang ◽  
Yann Fen C. Chao ◽  
Horng-Jyh Harn ◽  
...  

The purpose of this study was to compare whole blood and plasma in terms of the subsequent accuracy of blood lactate, glucose, lactate dehydrogenase (LDH), creatine phosphokinase (CPK), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) measurement. Blood samples were drawn from 8 male Wistar-Kyoto rats. The rats were homologous, weighed 300— 380 g, were housed in the same environment, and were provided with food and water under the same conditions. Blood draws occurred in all rats at same time. The blood specimens were divided into two samples, one to be stored as whole blood (WBS) and one to be stored as plasma (PS). All the blood sample analyses were performed by trained and experienced personnel to ensure that differences in results were due to variation in form in which specimens were stored rather than to technique. The lactate concentration in the WBS group gradually increased over time, intraclass correlation coefficient (ICC) = 0.541, 95% confidence interval (CI; —0.197, 0.893), and was higher than that of the PS group, ICC = 0.897, 95% CI (0.733, 0.976). By contrast, glucose level gradually declined for the WBS group, ICC= —0.367, 95% CI (—2.563, 0.682). Whole blood storage increased measurement variation for lactate, glucose, LDH, and CPK. Plasma storage prolonged the stability of the biochemical components. This study demonstrates the importance of evaluating validity at each stage of developing and testing animal models.


2009 ◽  
Vol 40 (12) ◽  
pp. 709-718 ◽  
Author(s):  
Valerie L. Hill ◽  
Virginia Z. Simpson ◽  
Jeanette M. Higgins ◽  
Zonghui Hu ◽  
Randy A. Stevens ◽  
...  

2018 ◽  
Vol 56 (3) ◽  
pp. 413-421 ◽  
Author(s):  
Anne Marie Dupuy ◽  
Jean Paul Cristol ◽  
Bruno Vincent ◽  
Anne Sophie Bargnoux ◽  
Mickael Mendes ◽  
...  

AbstractBackground:Blood specimens are transported from clinical departments to the biochemistry laboratory by hospital courier service, sometimes over long distances. The aim of this study was to assess the stability of common biochemical analytes in venous blood under our routine transport conditions and to evaluate analyte stability after prompt or delayed centrifugation.Methods:We investigated pre- and postanalytical contributions of 32 biochemical analytes in plasma and serum samples from 10 patients (healthy adults and patients from intensive care units). Differences in analyte concentrations between baseline (T0) and different time intervals (2, 4, 6, 8, 12 and 24 h) following storage after prompt and delayed centrifugation were reported. Evaluation was against the total change limit as described by Oddoze et al. (Oddoze C, Lombard E, Portugal H. Stability study of 81 analytes in human whole blood, in serum and in plasma. Clin Biochem 2012;45:464–9).Results:The majority of analytes were stable with delayed separation up to 12 h, except for potassium, C-peptide, osteocalcin, parathyroid hormone (PTH), bicarbonate and LDH. After prompt centrifugation and storage at 4°C, stability was greatly increased up to 48 h for most analytes. LDH and bicarbonate had the lowest stability after centrifugation; therefore, no reanalysis of these analytes in a centrifuged tube can be allowed.Conclusions:Knowledge of analyte stability is crucial to interpret biological analysis with confidence. However, centrifugation prior to transport is time consuming, and the transfer of plasma or serum from a primary tube to a secondary tube increases the risk of preanalytical errors. For analytes that are stable in whole blood for 24 h or more, it seems that there is no benefit to centrifuge before transport.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11207
Author(s):  
Pakkapon Rattanachaisit ◽  
Sirinporn Suksawatamnuay ◽  
Supachaya Sriphoosanaphan ◽  
Kessarin Thanapirom ◽  
Panarat Thaimai ◽  
...  

Background Hepatitis B virus (HBV) pregenomic RNA (pgRNA) has gained increasing attention owing to its role in replication of covalently closed circular DNA (cccDNA) in HBV. This marker has the potential to be used in clinical programs aimed to manage HBV infections. However, several reports on HBV pgRNA levels in clinical cases have conflicting results. RNA is easily degraded when exposed to heat and other environmental stressors. However, the stability of HBV pgRNA, during blood sample collection before the standard automated quantification, has never been estimated. This study aimed to demonstrate the effect of two different temperature conditions and storage durations on the stability of HBV pgRNA. Method Blood from forty patients with chronic hepatitis B infection, who also showed evidence of active HBV DNA replication, was collected and processed within 2 h of collection. Plasma from each patient was divided and stored at 4 °C and 25 °C (room temperature) for six different storage durations (0, 2, 6, 12, 24, and 48 h) and subsequently transferred to −80 °C for storage. The effect of multiple cycles of freezing and thawing of plasma at −20 °C or −80 °C was evaluated using samples from ten patients. Quantification of pgRNA from the samples was performed simultaneously, using the digital polymerase chain reaction (dPCR) method. The differences in pgRNA levels at baseline and each time point were compared using generalized estimating equation (GEE). A change greater than 0.5 log10 copies/mL of pgRNA is considered clinically significant. Statistical analyses were conducted using Stata 16.0. Results The mean HBV pgRNA level in the initially collected plasma samples was 5.58 log10copies/mL (ranging from 3.08 to 8.04 log10 copies/mL). The mean pgRNA levels in samples stored for different time periods compared with the initial reference sample (time 0) significantly decreased. The levels of pgRNA for 6, 12, 24, and 48 h of storage reduced by −0.05 log10 copies/mL (95% confidence interval (CI) −0.095 to −0.005, p = 0.03), −0.075 log10 copies/mL (95% CI [−0.12 to −0.03], p = 0.001), −0.084 log10 copies/mL (95% CI [−0.13 to −0.039], p =  < 0.001), and −0.120 log10 copies/mL (95% CI [−0.17 to −0.076], p =  < 0.001), respectively. However, these changes were below 0.5 log10 copies/mL and thus were not clinically significant. Compared with the samples stored at 4 °C, there were no significant differences in pgRNA levels in samples stored at 25 °C for any of the storage durations (−0.01 log10 copies/mL; 95% CI [−0.708 to 0.689], p = 0.98). No significant difference in the levels of pgRNA was observed in the plasma samples, following four freeze-thaw cycles at −20 °C and −80 °C. Conclusion The plasma HBV pgRNA level was stable at 4 °C and at room temperature for at least 48 h and under multiple freeze-thaw cycles. Our results suggest that pgRNA is stable during the process of blood collection, and therefore results of pgRNA quantification are reliable.


Author(s):  
Olof Beck ◽  
Maria Mellring ◽  
Christian Löwbeer ◽  
Sabina Seferaj ◽  
Anders Helander

AbstractPhosphatidylethanol (PEth) is a group of phospholipids formed in cell membranes following alcohol consumption by action of the enzyme phospholipase D (PLD). PEth measurement in whole blood samples is established as a specific alcohol biomarker with clinical and forensic applications. However, in blood specimens containing ethanol, formation of PEth may continue after sampling leading to falsely elevated concentrations. This study evaluated the use of dried blood spot (DBS) and microsampling specimens to avoid post-sampling formation of PEth. Filter paper cards and three commercial devices for volumetric microsampling of finger-pricked blood were assessed, using PEth-negative and PEth-positive whole blood fortified with 2 g/L ethanol. PEth (16:0/18:1) was measured by LC–MS/MS. Post-sampling formation of PEth occurred in wet blood and in the volumetric devices, but not filter paper cards, when stored at room temperature for 48 h. Addition of an inhibitor of PLD, sodium metavanadate (NaVO3), eliminated post-sampling formation during storage and drying. In conclusion, the present study confirmed previous observations that PEth can be formed in blood samples after collection, if the specimen contains ethanol. The results further demonstrated that post-sampling formation of PEth from ethanol also occurred with commercial devices for volumetric dried blood microsampling. In order for a PEth result not to be questioned, it is recommended to use a PLD inhibitor, whether venous blood is collected in a vacutainer tube or finger-pricked blood is obtained using devices for dried blood microsampling. Graphical abstract


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