Stability of immunologic activity of human prostatic acid phosphatase in serum.

1982 ◽  
Vol 28 (5) ◽  
pp. 1163-1166 ◽  
Author(s):  
I W Chen ◽  
M I Sperling ◽  
H R Maxon ◽  
L A Kaplan
Keyword(s):  
Acid Phosphatase ◽  
Room Temperature ◽  
Chelating Agent ◽  
Prostatic Acid Phosphatase ◽  
Storage Conditions ◽  
Enzymic Activity ◽  
Serum Samples ◽  
Long Term Storage ◽  
The Stability ◽  
Immunologic Activity

Abstract The stability of the immunologic activity of human serum prostatic acid phosphatase (iPAP;EC 3.1.3.2) under various storage conditions was evaluated. Although more stable than the enzymic activity of serum PAP, serum iPAP was inactivated rapidly at room temperature at neutral and especially at alkaline pH. Purified iPAP in a phosphate buffer (pH 7.5) was stable for at least three days at room temperature but showed instability similar to that of serum iPAP when added to heat-treated serum (30 min at 56 degrees C, pH 8.3). Addition of a protease inhibitor, a sulfhydryl agent, or a chelating agent failed to preserve iPAP. Acidification of serum with an acetate buffer (5 mol/L, pH 5.0), 20 microliters/mL of serum, protected but could not restore serum iPAP activity. When stored at 24 degrees C, serum iPAP was most stable at pH 6.5. Acidification had little effect on PAP values by radioimmunoassay, iPAP values from acidified and unacidified serum samples being essentially the same. We recommend that blood samples drawn for PAP immunoassays be kept at 4 degrees C and that serum samples be separated and acidified as soon as practical. For long-term storage, acidified serum samples should be kept in small aliquots at -20 or -70 degrees C.

scholarly journals Changes of salivary biomarkers under different storage conditions: effects of temperature and length of storage

2018 ◽  
Vol 29 (1) ◽  
pp. 94-111 ◽  
Author(s):  
Tomás Barranco ◽  
Asta Tvarijonaviciute ◽  
Damián Escribano ◽  
Fernando Tecles ◽  
José J Cerón ◽  
...  
Keyword(s):  
Antioxidant Capacity ◽  
Room Temperature ◽  
Storage Conditions ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Long Term Storage ◽  
Reducing Ability ◽  
Trolox Equivalent ◽  
The Stability ◽  
Term Storage

Introduction: In this report, we aimed to examine the stability of various analytes in saliva under different storage conditions. Materials and methods: Alpha-amylase (AMY), cholinesterase (CHE), lipase (Lip), total esterase (TEA), creatine kinase (CK), aspartate aminotransferase (AST), lactate dehydrogenase (LD), lactate (Lact), adenosine deaminase (ADA), Trolox equivalent antioxidant capacity (TEAC), ferric reducing ability (FRAS), cupric reducing antioxidant capacity (CUPRAC), uric acid (UA), catalase (CAT), advanced oxidation protein products (AOPP) and hydrogen peroxide (H2O2) were colorimetrically measured in saliva obtained by passive drool from 12 healthy voluntary donors at baseline and after 3, 6, 24, 72 hours, 7 and 14 days at room temperature (RT) and 4 ºC, and after 14 days, 1, 3 and 6 months at – 20 ºC and – 80 ºC. Results: At RT, changes appeared at 6 hours for TEA and H2O2; 24 hours for Lip, CK, ADA and CUPRAC; and 72 hours for LD, Lact, FRAS, UA and AOPP. At 4 ºC changes were observed after 6 hours for TEA and H2O2; 24 hours for Lip and CUPRAC; 72 hours for CK; and 7 days for LD, FRAS and UA. At – 20 ºC changes appeared after 14 days for AST, Lip, CK and LD; and 3 months for TEA and H2O2. At – 80 ºC observed changes were after 3 months for TEA and H2O2. Conclusions: In short-term storage, the analytes were more stable at 4 ºC than at room temperature, whereas in long-term storage they were more stable at - 80 ºC than at – 20 ºC.

Human plasma stability during handling and storage: impact on NMR metabolomics

The Analyst ◽  
2014 ◽  
Vol 139 (5) ◽  
pp. 1168-1177 ◽  
Author(s):  
Joana Pinto ◽  
M. Rosário M. Domingues ◽  
Eulália Galhano ◽  
Cristina Pita ◽  
Maria do Céu Almeida ◽  
...  
Keyword(s):  
Human Plasma ◽  
Room Temperature ◽  
Storage Conditions ◽  
Plasma Composition ◽  
Long Term Storage ◽  
Short And Long Term ◽  
The Stability ◽  
And Storage ◽  
Term Storage

The stability of human plasma composition was investigated by NMR, considering different collection tubes, time at room temperature (RT), short- and long-term storage conditions and up to 5 consecutive freeze–thaw cycles.

scholarly journals Effect of Storage Temperature and Time on Stability of Liver Enzymes in Blood Serum

2020 ◽  
Vol 23 (5) ◽  
pp. 296-301
Author(s):  
Shadi Kolahdoozan ◽  
Sadaf G. Sepanlou ◽  
Maryam Sharafkhah ◽  
Elaheh Shaker ◽  
Ameneh Shayanrad ◽  
...  
Keyword(s):  
Linear Models ◽  
Liver Enzymes ◽  
Storage Temperature ◽  
Linear Regression Analysis ◽  
Storage Conditions ◽  
Prolonged Storage ◽  
Serum Samples ◽  
Long Term Storage ◽  
The Stability ◽  
Almost All

Background: It is increasingly common to collect and store specimens for future unspecified research. However, the effects of prolonged storage on the stability and quality of analytes in serum have not been well investigated. We aimed to determine whether the stability of liver enzymes extracted from frozen bio-samples stored at the baseline is affected by storage conditions. Methods: A total of four liver enzymes in the sera of 400 patients were examined following storage. After deter-mining the baseline measurements, the serum of each patient was aliquoted and stored at −70°C for three and six months, as well as one, two, and five years after collecting the original sample. The percent change from baseline measurements was calculated both statistically and clinically. Linear models were also used to correct the results of the samples based on the time they were frozen. Results: In almost all samples, liver enzymes were detectable until two years after the baseline, while in a signifi-cant proportion of samples, enzymes were not ultimately detectable five years after the baseline. Linear regression analysis on log-transformed levels of enzymes shows that the performance is acceptable until one year after the baseline. The performance of the prediction model declines substantially two and five years after the baseline, except for GGT. Conclusion: Long-term storage of serum samples significantly decreases the concentration of the liver enzymes from the baseline, except for GGT. It is not recommended to store samples for more than two years, as liver en-zymes are not detectable afterwards.

The Stability of Creatine Kinase Isoenzymes Studied with Two-Site Monoclonal Antibody Assays

1985 ◽  
Vol 22 (3) ◽  
pp. 310-315 ◽  
Author(s):  
A P Jackson ◽  
R J Thompson
Keyword(s):  
Monoclonal Antibody ◽  
Creatine Kinase ◽  
Room Temperature ◽  
Storage Conditions ◽  
Normal Serum ◽  
Serum Samples ◽  
Subunit Dissociation ◽  
Creatine Kinase Isoenzymes ◽  
Antibody Assays ◽  
The Stability

The stability of human creatine kinase isoenzymes was investigated under different storage conditions using specific two-site monoclonal antibody assays. In Tris-HCl buffer pH 7·5 or barbitone buffer pH 8·1 containing 5 g/L bovine serum albumin, the isoenzymes appeared to be stable for up to 3 weeks at 4°C but suffered a partial subunit dissociation and random reassociation after freeze–thawing; this dissociation was more pronounced as a result of freezing at −20°C rather than at −70°C. In contrast, creatine kinase isoenzymes stored in serum were stable at both 4°C and following freeze-thawing. High levels of heart type creatine kinase in serum showed only minor subunit hybridisation even after 12 h at room temperature. We conclude that in practical clinical situations, subunit hybridisation in serum samples is negligible. We recommend however, that isoenzyme standards for use in either two-site assays or radioimmunoassays should be stored frozen in normal serum from which endogenous creatine kinase isoenzymes have been previously removed.

Stability of extemporaneously prepared rosuvastatin oral suspension

2017 ◽  
Vol 74 (19) ◽  
pp. 1579-1583 ◽  
Author(s):  
Abdel Naser Zaid ◽  
Rania Shtayah ◽  
Ayman Qadumi ◽  
Mashour Ghanem ◽  
Rawan Qedan ◽  
...  
Keyword(s):  
Relative Humidity ◽  
High Performance ◽  
Room Temperature ◽  
Microbial Contamination ◽  
Active Pharmaceutical Ingredient ◽  
Storage Conditions ◽  
Dissolution Profile ◽  
Stability Studies ◽  
Organoleptic Properties ◽  
The Stability

Abstract Purpose The stability of an extemporaneously prepared rosuvastatin suspension stored over 30 days under various storage conditions was evaluated. Methods Rosuvastatin suspension was extemporaneously prepared using commercial rosuvastatin tablets as the source of active pharmaceutical ingredient. The organoleptic properties, dissolution profile, and stability of the formulation were investigated. For the stability studies, samples of the suspension were stored under 2 storage conditions, room temperature (25 °C and 60% relative humidity) and accelerated stability chambers (40 °C and 75% relative humidity). Viscosity, pH, organoleptic properties, and microbial contamination were evaluated according to the approved specifications. High-performance liquid chromatography was used for the analysis and quantification of rosuvastatin in selected samples. Microbiological investigations were also conducted. Results The prepared suspension showed acceptable organoleptic properties. It showed complete release of rosuvastatin within 15 minutes. The pH of the suspension was 9.8, which remained unchanged during the stability studies. The microbiological investigations demonstrated that the preparation was free of any microbial contamination. In addition, the suspension showed stability within at least the period of use of a 100-mL rosuvastatin bottle. Conclusion Extemporaneously prepared rosuvastatin 20-mg/mL suspension was stable for 30 days when stored at room temperature.

scholarly journals The Influence of Serum Sample Storage Conditions on Selected Laboratory Parameters Related to Oxidative Stress: A Preliminary Study

Diagnostics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 51
Author(s):  
Lilla Pawlik-Sobecka ◽  
Katarzyna Sołkiewicz ◽  
Izabela Kokot ◽  
Aleksandra Kiraga ◽  
Sylwia Płaczkowska ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Serum Sample ◽  
Storage Conditions ◽  
Wilcoxon Test ◽  
Reference Ranges ◽  
Sample Storage ◽  
Serum Samples ◽  
The Stability ◽  
The Individual ◽  
The Impact

The present work aims at accessing the stability of biological material stored for diagnostic and scientific purposes. The influence of the temperature, storage time, and cyclic thawing on concentration stability of selected oxidative stress parameters in human serum was investigated. The study group consisted of 20 serum samples collected from healthy volunteers aged 18–52. The parameters whose reference ranges were not determined and to which validated determination methods did not correspond were examined by manual methods (FRAP and AOPP). Automatic methods were used to determine routine laboratory tests (albumin, total protein, bilirubin, uric acid) using the Konelab 20i® analyzer. The samples were stored at various temperatures (room temperature, 4 °C, −20 °C, −80 °C) for max 6 months and were subjected to cyclic thawing at 1 month intervals. In order to check whether any differences between the concentrations of the studied parameters existed when the samples were stored in various conditions, the paired Student t-test or Wilcoxon test and comparison to desirable bias were applied. Based on the obtained results, it was found that the temperature and time of serum sample storage significantly affected the stability of the analyzed parameters and determined different shelf lives of serum samples for oxidative stress examination. Therefore, continuing the investigation concerning the impact of storage conditions on various serum parameters seems justified due to the discrepancy between the individual results obtained by different researchers and the inconsistencies between the results of scientific research and the applicable recommendations.

Spectrophotometric and liquid-chromatographic studies of thymolphthalein monophosphate. Specifications for high-quality substrate for the measurement of prostatic acid phosphatase activity.

1981 ◽  
Vol 27 (8) ◽  
pp. 1372-1377 ◽  
Author(s):  
G N Bowers ◽  
M Onoroski ◽  
R S Schifreen ◽  
L R Brown ◽  
R E Klem ◽  
...  
Keyword(s):  
Acid Phosphatase ◽  
Phosphatase Activity ◽  
Acid Phosphatase Activity ◽  
Prostatic Acid Phosphatase ◽  
Enzymic Activity ◽  
Disodium Salt ◽  
Critical Importance ◽  
High Quality ◽  
Activity Measurements ◽  
Liquid Chromatographic

Abstract Fourteen lots of thymolphthalein monophosphate (TMP), disodium salt, obtained from 10 commercial suppliers were compared spectrophotometrically at 445 and 595 nm, liquid-chromatographically with monitoring at 254 nm, and enzymically by measurements of activity of prostatic acid phosphatase in human serum. Eight lots were classified as "unacceptable," six as "acceptable." Spectrophotometric testing revealed four lots with excessive thymolphthalein and three lots with grossly deficient amounts of TMP. In general, the chromatographic results paralleled those obtained by spectrophotometry, and both results correlated well with enzymic activity. Changing water content in this hygroscopic salt was a major problem, which resulted in great uncertainty as to the formula weight and therefore as to the moles of TMP actually taken. From these studies, specifications for high-quality TMP were determined. The critical importance of simultaneous enzymic activity measurements in comparisons with other "acceptable" lots in defining an adequate TMP substrate is stressed. Use of these specifications for selecting TMP for acid phosphatase activity measurements should improve intra- and inter-laboratory analytical performance.

Development and evaluation of a new solid-phase direct immunoenzyme assay for prostatic acid phosphatase.

1982 ◽  
Vol 28 (4) ◽  
pp. 596-602 ◽  
Author(s):  
K Gericke ◽  
K P Kohse ◽  
G Pfleiderer ◽  
S H Flüchter ◽  
K H Bichler
Keyword(s):  
Acid Phosphatase ◽  
Prostatic Cancer ◽  
Solid Phase ◽  
Human Kidney ◽  
Prostatic Acid Phosphatase ◽  
Enzymic Activity ◽  
Organ Specificity ◽  
Polystyrene Tube ◽  
Prostatic Diseases ◽  
Independent Distribution

Abstract In this assay we used polystyrene-tube-attached rabbit antibodies against prostatic acid phosphatase (PAP) that had been purified to homogeneity from human prostate. The amount of immunoreactive acid phosphatase was determined directly by its enzymic activity in the solid-phase-bound immune complex. The detection limit was 0.05 U/L (0.13 microgram/L), the CVs between 4.3 and 10.8%. Investigating the organ specificity of PAP, we found that some cross-reacting acid phosphatase activity could be so measured in human kidney, leukocytes, and platelets, all of which probably contribute to the circulating "prostatic" acid phosphatase that normally is present in serum. Diurnal and day-to-day variations in serum PAP activity were as much as 100% in healthy subjects. Individuals without prostatic diseases (n = 92) had values for serum PAP activity up to 0.36 U/L (0.94 microgram/L), in an age-independent distribution; patients with benign prostatic hyperplasia (n = 62) showed values up to 0.48 U/L (1.25 micrograms/L). With PAP activity of 0.38 U/L or 1.0 microgram/L (90th percentile of the prostatic group) as the upper limit of "normality," overall sensitivity (stages A-D) for detection of prostatic cancer in 33 essentially untreated patients was 65%. Examples for the followup of therapy of prostatic cancer by measurement of serum PAP with this assay are described.

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