Evaluation of three different specimen types (serum, plasma lithium heparin and serum gel separator) for analysis of certain analytes: clinical significance of differences in results and efficiency in use.

BACKGROUND: There is a lack of consensus regarding the most appropriate specimen type for analysis of many biochemistry analytes. The aim of this study was to compare renal and lipid analyte profiles and phenytoin values in plain serum (S), serum gel (G) and plasma (lithium heparin, P) tubes and to investigate the stability of these analytes after prolonged contact with cells or gel at room temperature (RT, 20 degrees C) and as aliquoted and stored at 4 degrees C. METHODS: Primary specimens were centrifuged once, maintained at RT and analysed within 2 h (T(0)) and after 24 h (T(24)) and 48 h (T(48)). For assessment of stability at 4 degrees C, two cell-free aliquots were separated from each of the primary tubes and stored at 4 degrees C and then analysed at T(24) and T(48). Differences in analyte concentrations between tubes at T(0) and following storage (at T(24) and T(48)) were evaluated for both statistical and clinical significance. RESULTS: At T(0) all analytes, except potassium, demonstrated equivalence between serum, gel and plasma tubes. Potassium and creatinine were more stable in gel tubes than in serum/plasma tubes. In contrast, phentytoin was stable in plain serum and plasma up to T(48) at RT, but showed a progressive and clinically significant decrease in concentration in gel tubes at T(24) and T(48) at RT. All analytes except CO(2) were stable up to T(48) when aliquoted and stored at 4 degrees C. CONCLUSIONS: We concluded that the serum gel tube has advantages over plain serum and plasma tubes for measurement of the analytes investigated in this study, with the exception of phenytoin. In practice, the gel tubes demonstrate enhanced analyte stability and reduce the need to aliquot specimens, with greater protection against possible contamination. Further investigation would be required to evaluate a broader range of analytes.     

Storage of whole blood: effect of temperature on the measured concentration of analytes in serum

We measured the concentrations of 29 commonly measured analytes in fresh sera and in sera that had been stored as whole blood at seven different temperatures for 24 h. We determined the effect of storage temperature and prolonged contact with cell clot on the measured concentration of each analyte, with fresh serum as the control. Significant differences were observed for concentrations of creatinine, glucose, inorganic phosphorus, potassium, and both aminotransferases. The extent of these differences was temperature dependent. Values for the remaining 23 analytes examined were essentially unaffected by the storage.     

Evaluation of BD Vacutainer SST™ II Plus tubes for common tumor marker tests by Roche Diagnostics Modular E 170 analyzer

Serum separator tubes were introduced 35 years ago and were widely used in the clinical laboratory in China for routine collection of blood because of providing a closed system that allowed for collection, transport, processing, sampling, and storage of specimens. This type of tubes facilitated rapid separation of serum from cellular constituents of blood and also prevented hemolysis upon prolonged storage. However, there were some limitations associated with gel tubes (i.e., gel and analyte stability). In order to circumvent these problems, BD released a new serum separator tube containing a new gel (BD SST^? II Plus). We investigated theperformance of BD SST^? II Plus tubes for tumor marker tests using BD Serum Glass tubes as controls. Equivalence between the BD SST^? II Plus and BD Serum Glass tubes was demonstrated for all analytes at initial time. Also, all analytes remained stable when stored in BD SST^? II Plus tubes up to 72 hr. Concentration of neuron‐specific enolase tended to increase with preservation time up to 72 hr in BD Serum Glass tubes. We conclude that BD SST^? II Plus was suitable for collection of blood and storage of serum for tumor marker tests. J. Clin. Lab. Anal. 24:418–421, 2010. © 2010 Wiley‐Liss, Inc.     

Comparison of BD Vacutainer SST Plus Tubes with BD SST II Plus Tubes for common analytes

Serum separator tubes were introduced 25 years ago and are widely used in the clinical laboratory today for routine collection of blood. These tubes have gained widespread acceptance due to the advantage of the barrier gel that facilitates rapid separation of serum from cellular constituents of blood and thus reduces hemolysis. However, there are some limitations associated with gel tubes (i.e., gel stability and analyte incompatibilities). The serum separator BD SST tubes manufactured by BD are widely used in clinical laboratories. Recently, BD has developed a new barrier gel, which is superior to the existing gel. We studied the stability of common analytes when serum specimens were stored in the new BD SST II tubes by comparing the performance with the existing BD SST tubes. We did not observe any significant reduction in concentrations of 42 commonly ordered analytes using the new BD SST II tubes. Significant differences were noted at low serum volumes for estradiol in both tube types over time. We conclude that the new BD SST II tubes are suitable for collection of blood and storage of serum for commonly ordered laboratory tests.     

Evaluation of a new blood-collecting device ("microtainer") that is suited for pediatric use.

We evaluated the prototype of a "Microtainer" (800-mul) tube (Becton-Dickinson Co., Rutherford, N.J. 07070), In which a semi-solid silicone material is used to separate serum from erythrocytes on centrifugation. We compared results for 18 serum analytes with those obtained for specimens collected by the "dripping" method of capillary blood collection. The serum was examined microscopically for platelets and leukocytes from both normal and leukemic specimens. The cellular elements were all contained in the erythrocyte layer. Hemolysis was negligible. Means for paired samples did not differ significantly, except for Na+, for which the difference was not clinically significant. Values for potassium and lactate dehydrogenase were unchanged 24 h after collection, even though the serum was left in the collecting device.     

Evaluation of BD Vacutainer SST™ II plus tubes for special proteins testing

In the past few years, because of providing a closed system that allowed for collection, transport, processing, sampling, and storage of specimens, serum separator tubes gained widespread acceptance gradually in China. However, some limitations associated with gel tubes had been observed, for example, gel and analyte stability. In order to circumvent these problems, a new tube (BD Vacutainer^® SST? II Plus (BD SST? II Plus)) containing a new gel was released by BD with respect to analyte and gel stability. We investigated the performance of BD SST? II Plus tubes for special proteins testing using BD Vacutainer^® Serum Glass Tubes (BD Serum Glass) as controls.Equivalence between these two types of tubes was demonstrated for all analytes at initial time, and data for all analytes except complement 3 (C3) and complement 4 (C4) indicated comparable stability over time in these two types of tubes. Concentration of C3 and C4 tended to increase with preservation time up to 72 hr in BD Serum Glass tubes. The stability of C3 and C4 was better in BD SST? II Plus, which was demonstrated at timepoints up to 48 hr. We conclude that BD SST? II Plus was suitable for collection and storage of samples for special proteins testing. J. Clin. Lab. Anal. 25:203–206, 2011. © 2011 Wiley‐Liss, Inc.     

An approach to analytical validation and testing of body fluid assays for the automated clinical laboratory

BackgroundBiochemical analysis of body fluids may lend insight into the pathogenesis of disease. Most commercially-available clinical laboratory methods are intended for blood-derived specimens and/or urine and laboratories must characterize the analytical performance of these methods for other specimen types such as body fluids. The aim of this work is to demonstrate one approach for characterizing analytical performance of assays for clinical analysis of body fluids.MethodsResidual waste samples were obtained from clinically ordered testing. Validation studies were performed for 8 chemistry analytes on Roche Cobas 6000 c501 (Roche Diagnostics, Inc.) analyzers. Accuracy, precision, analytical measurable range, reportable range, analytic sensitivity, interferences, analyte stability were assessed. Laboratory workflow for body fluid handling was designed based on results obtained.ResultsSample matrix interferences were not observed for the body fluids tested and assay reportable ranges used for serum were validated for body fluids. Dilution of body fluid specimens with saline demonstrated non-linear recovery of some enzyme activities. Assay imprecision was comparable to the manufacturer's claims for serum. The serum index thresholds for interference from hemoglobin and lipemia were lower for body fluids compared to manufacturer's stated limits for serum. Pretreatment of body fluid samples with hyaluronidase caused a 28% false increase in lipase activity, and 13% increase in total protein concentration. Ambient temperature analyte stability in body fluids was ≤24 h for most analytes compared to manufacturer's stated stability of 7 days for serum. In contrast to serum, lactate dehydrogenase (LDH) was labile in frozen body fluid specimens.ConclusionsValidation of analytical methods for body fluid testing is a necessary exercise to exclude potential matrix effects and set pre-analytic specimen quality criteria.     

Hormone stability in human whole blood

OBJECTIVE: To determine whether significant changes in the plasma concentrations of 17 hormones occur when human whole blood is held at 4 or 24 degrees C for up to 24 h before separation of the plasma fraction. DESIGN AND METHODS: Blood samples (EDTA) from healthy human volunteers were held at 4 degrees C or 24 degrees C for 0.5, 6 or 24 h before separation. Plasma concentrations of ACTH, aldosterone, gonadotrophin alpha-subunits, AVP, C-peptide, estradiol, FSH, GH, glucagon, IGF-1, IGFBP3, insulin, leptin, LH, prolactin, PTH and VIP were measured and the results compared to baseline values. Nonlinear regression was used to test for a significant mean rate of change. The time interval for median concentrations to change by 10% was determined. RESULTS: Significant changes were observed for ACTH (decrease at 18.6 hr, 4 degrees C; 17.5 hr, 24 degrees C); AVP (increase at 2.6 h, 24 degrees C); insulin (decrease at 16.8 hr, 4 degrees C; 16.9 hr, 24 degrees C) and VIP (increase at 18.6 h, 24 degrees C). No changes were detected for the remaining analytes.B CONCLUSIONS: The measurement of some hormones is compromised by a delay in plasma separation from normal human blood. While many hormones appear stable in normal whole blood, we recommend that processing occurs without delay.     

Different stability of free and complexed prostate-specific antigen in serum in relation to specimen handling and storage conditions.

The effect of sample collection, storage conditions (time and temperature), and freeze-thaw cycles on the stability of free prostate-specific antigen (fPSA), PSA complexed with alpha1-antichymotrypsin (ACT-PSA), and total PSA (tPSA) in serum was studied. The analytes were quantified using immunoassays for tPSA and fPSA on the Elecsys system 2010 and a research assay for ACT-PSA on the ES system (Roche Diagnostics). The stability of the analytes was calculated as percentages of the values measured in samples 1 h after blood collection. When the samples were stored at 37 degrees C, at room temperature or at 4 degrees C, the stability of ACT-PSA was less impaired than that of fPSA. To avoid erroneous results in the determination of PSA isoforms and their corresponding ratios, serum samples should be preserved at 4 degrees C when the analysis is performed within 8 h after blood collection, or they should be stored at -80 degrees C if the analysis is not feasible during that period.     

Glucose variation in centrifuged serum and lithium-heparin gel tubes stored for up to 96 hours at room temperature or 4 °C

Abstract

This study aimed to verify glucose stability within centrifuged serum and lithium-heparin tubes stored at room temperature (RT) or 4?°C. Sixty paired serum (plus gel separator), lithium-heparin (plus gel separator) and K₂-EDTA tubes were centrifuged within 30?min from collection. Thirty serum and lithium-heparin tubes were then stored at RT, whilst the other 30 serum and lithium-heparin tubes were kept at 4?°C. Complete cell blood count was performed in serum and plasma after centrifugation, as well as in K₂-EDTA paired whole blood tubes. Glucose was measured immediately after centrifugation and 3, 6, 24, 48, 72 and 96?h afterwards. Immeasurable blood cells values were found in serum, whilst residual leukocytes and platelets were present in lithium-heparin plasma. Regardless of storage conditions, glucose concentration decreased 3?h after centrifugation in lithium-heparin tubes, displaying uninterrupted reduction until 96?h. Mean decrease per hour was higher in plasma tubes stored at RT than at 4?°C. Performance specification was exceeded between 6 and 24?h of storage in most plasma tubes. Glucose concentration significantly decreased in serum tubes between 24 and 48?h, regardless of storage conditions. The mean glucose variation never exceeded performance specification throughout the study period. Mean glucose decrease per hour in plasma was not associated with blood cells counts before and after centrifugation, and was probably attributable to the presence of blood cells entrapped within the gel. Delayed glucose measurement in centrifuged serum tubes may be clinically viable up to 96?h, whilst it may be unadvisable in centrifuged lithium-heparin tubes.     

Stability of prothrombin time and activated partial thromboplastin time tests under different storage conditions

Prothrombin time (PT) and activated partial thromboplastin time (aPTT) are common laboratory tests that are useful in the diagnosis of coagulation disorders and monitoring anticoagulant therapy. Recent expansions in the outreach laboratory services at our institution prompted us to investigate the shipping limitations for some tests, including PT and aPTT. Although we followed NCCLS guidelines for the collection of blood specimens, we observed falsely elevated PT and aPTT values due to the different storage conditions. The objective of this study is to determine the effect of conditions and duration of storage on PT and aPTT tests using plasma and whole blood samples, respectively. For this study, 36 plasma samples with normal and prolonged PT and aPTT were exposed to different storage conditions. Blood was centrifuged immediately and plasma was stored at room temperature (RT), refrigerated at 4°C, or frozen at −20°C. The samples were analyzed at 0 h and repeated at 6, 12 and 24 h under various conditions. Although statistically significant differences were observed for plasma samples for normal PT tests after 12 h at refrigerated and frozen storage conditions, the differences would not change the clinical interpretation of the results. On the other hand, samples stored refrigerated or at RT showed significant differences for aPTT at 24 h. These differences would change clinical interpretation, especially for samples with normal or near normal aPTT times. Interestingly, aPTT was significantly higher for samples stored frozen when compared to refrigerated and RT conditions at 6 h. Similar patterns were also observed on ten whole blood samples with normal PT and aPTT values. In conclusion, either plasma or whole blood samples can be accepted for PT testing up to 24 h and for aPTT testing up to 12 h only, when transported either at RT or at 4°C.     

Methamphetamine and amphetamine pharmacokinetics in oral fluid and plasma after controlled oral methamphetamine administration to human volunteers

BACKGROUND: Methamphetamine (METH) and amphetamine (AMP) concentrations in 200 plasma and 590 oral fluid specimens were used to evaluate METH pharmacokinetics and pharmacodynamics after oral administration of sustained-release METH. METHODS: Eight participants received four oral 10-mg S-(+)-METH hydrochloride sustained-release tablets within 7 days. Three weeks later, five participants received four oral 20-mg doses. Blood samples were collected for up to 24 h and oral fluid for up to 72 h after drug administration. RESULTS: After the first oral dose, initial plasma METH detection was within 0.25-2 h; c(max) was 14.5-33.8 micro g/L (10 mg) and 26.2-44.3 micro g/L (20 mg) within 2-12 h. In oral fluid, METH was detected as early as 0.08-2 h; c(max) was 24.7-312.2 micro g/L (10 mg) and 75.3-321.7 micro g/L (20 mg) and occurred at 2-12 h. The median oral fluid-plasma METH concentration ratio was 2.0 across 24 h and was highly variable. Neutral cotton swab collection yielded significantly higher METH and AMP concentrations than citric acid candy-stimulated expectoration. Mean (SD) areas under the curve for AMP were 21% +/- 25% and 24% +/- 11% of those observed for METH in plasma and oral fluid, respectively. After a single low or high dose, plasma METH was >2.5 micro g/L for up to 24 h in 9 of 12 individuals (mean, 7.3 +/- 5.5 micro g/L at 24 h); in oral fluid the detection window was at least 24 h (mean, 18.8 +/- 18.0 micro g/L at 24 h). The plasma and oral fluid 24-h METH detection rates were 54% and 60%, respectively. After four administrations, METH was measurable for 36-72 h (mean, 58.3 +/- 14.5 h). CONCLUSIONS: Perceived advantages of oral fluid for verifying METH exposure compared with urine include simpler specimen collection and reduced potential for adulteration, but urine offers higher analyte concentrations and a greater window of detection.     

The alterations of the activities of coagulation inhibitors and fibrinolytic factors in stored cord blood could affect the yield of progenitor cells during processing

We assessed the changes in the activities of hemostatic variables by the storage temperature and time interval between collection and separation of cord blood (CB) and analyzed their relationship with the yield of progenitor cells during processing. Total nucleated cell (TNC) and CD34+ cell counts were significantly higher in the CB stored at ambient temperature than at 4 degrees C. The significant loss of TNC and CD34+ cells continued to 24 h after collection in CB stored at 4 degrees C, but loss of TNC began only after 24 h at ambient temperature. There were no changes in the plasma activities of antithrombin III (ATIII) and plasminogen. The activity of protein C was decreased significantly until 24 h after collection, particularly in CB stored at 4 degrees C. The activity of alpha2-antiplasmin was decreased until 24 h in CB stored at 4 degrees C and from 24 h in CB stored at ambient temperature. These data suggest that the alterations in the activities of coagulation inhibitors and fibrinolytic factors could be an important factor in coagulability, particularly in CB stored at 4 degrees C compared to ambient temperature, and also affect the yield of progenitor cells in processed CB.     

存放时间和温度对凝血功能指标检测结果的影响

目的 探讨标本放置时间和温度对凝血酶原时间(PT)、活化部分凝血活酶时间(APTT)、凝血酶时间(TT)、纤维蛋白原(FⅠB)等凝血指标检测结果的影响.方法 选取抗凝静脉血标本50例,血浆用于立即测定凝血4项指标和在室温放置2 h、4 h、6 h和24 h后测定凝血4项指标;并分别于室温、-4 ℃和-20 ℃下保存24 h后测定凝血4项指标.抗凝血室温放置2 h,离心分离血浆后即刻进行凝血指标检测.采用血液凝固仪测定研究指标,采用随机单位组设计资料方差分析比较各组间差异.结果 与留取即刻检测相比,血浆放置2 h APTT、PT、TT和FⅠB等各种指标水平均无明显差异;血浆标本放置4 h开始,APTT、PT和TT等指标出现明显延长,且变化程度随放置时间延长加重,FⅠB水平无明显改变;抗凝血标本放置2 h留取的血浆标本各指标均有明显变化.-4 ℃下血浆标本保存24 h APTT、PT、TT和FⅠB等指标测定结果未出现明显改变,-20 ℃下24 h APTT出现明显延长.结论 对于凝血功能4项指标的测定,采集标本后应及时送检和尽快分离血浆.常温下血浆标本应在2 h内完成测定;-4 ℃下血浆标本保存24 h PT、APTT、TT和FⅠB等指标测定结果未受影响,低温保存应注意避免标本冻融过程.     

标本类型和储存条件对促肾上腺皮质激素检测结果稳定性的影响

目的探讨标本类型和储存条件对促肾上腺皮质激素(ACTH)检测结果稳定性的影响。方法将标本分成血浆组和血清组,每组各57例,并在抽血后1h内检测ACTH浓度。在血浆组中选取30例血浆量充足的标本分成室温组、冷藏组和冷冻组,每组各30例,其中室温组和冷藏组在2、24、121h时检测ACTH浓度,冷冻组在24、121h时检测ACTH浓度。检测结果与设定的标准值进行比较分析。结果血清组ACTH水平明显低于血浆组,差异有统计学意义(P0.05)。室温组在2、24、121h时的检测结果与标准值比较差异有统计学意义(P0.05);冷藏组在2、24h时的检测结果与标准值比较差异无统计学意义(P0.05),而在121h时的检测结果与标准值比较差异有统计学意义(P0.05);冷冻组在24、121h时的检测结果与标准值比较差异无统计学意义(P0.05)。结论采用乙二胺四乙酸二钾抗凝标本检测ACTH时,在低温下应于1h内完成检测;若24h内不能完成检测时,应将分离的血浆冷冻储存于-20℃,其在121h内检测结果变化相对稳定。     

Plasma adiponectin is modestly decreased during 24-hour insulin infusion but not after inhibition of lipolysis by Acipimox

OBJECTIVE: Plasma adiponectin is associated with insulin resistance and atherosclerosis. Adiponectin expression in adipose tissue is up-regulated by peroxisome proliferator-activated receptor (PPAR)-gamma agonist treatment and its plasma level may be affected by insulin. We tested the hypothesis that prolonged exogenous insulin infusion decreases plasma adiponectin, and examined whether a possible effect of insulin on plasma adiponectin is attributable to inhibition of lipolysis. MATERIAL AND METHODS: The effect of insulin infusion on plasma adiponectin (Linco enzyme-linked immunosorbent assay) was evaluated during a 24-h moderately hyperinsulinemic clamp (8.3 microU kg(-1) s(-1)) in 8 male type 2 diabetic patients and in 8 healthy men. On a separate day, acipimox (250 mg/4 h for 24 h) was administered to inhibit lipolysis. Insulin and acipimox were administered in random order with 1 week between study days. RESULTS: In type 2 diabetic patients, insulin infusion decreased plasma adiponectin from 7.74+/-2.53 mg/l to 6.76+/-2.41 mg/l after 24 h (p<0.05). In healthy subjects, the change in plasma adiponectin after 24 h of insulin was not significant (8.10+/-2.76 and 7.55+/-2.41 mg/l at baseline and after 24 h of insulin, respectively). The change in plasma adiponectin after 24 h insulin in healthy subjects was not different from the change in diabetic patients. Plasma adiponectin did not decrease after 24 h acipimox administration in either group (type 2 diabetic patients: 6.84+/-2.19 and 6.54+/-2.93 mg/l at baseline and after 24 h, respectively (NS); healthy subjects; 7.35+/-2.52 and 8.31+/-3.37 mg/l, at baseline and after 24 h, respectively (NS)). When the results from diabetic and healthy subjects were combined, the decrease in plasma adiponectin after 24 h of insulin infusion (-0.76+/-1.08 mg/l, equivalent to a -9% change from baseline, p<0.05) was different (p = 0.05) from the change after 24 h acipimox (+0.33+/-1.74 mg/l, equivalent to a +4% change from baseline). Plasma free fatty acids decreased during insulin infusion (p<0.01 for both groups after 24 h) as well as in response to acipimox (p<0.05 for healthy subjects; p<0.01 type 2 diabetic patients after 24 h). After administration of acipimox, plasma insulin did not change in either group. CONCLUSIONS: Plasma adiponectin is modestly decreased during 24 h of insulin infusion. It is unlikely that this response to exogenous insulin is attributable to inhibition of lipolysis, since plasma adiponectin did not decrease after acipimox.     

Monoject Samplette capillary blood container with serum separator evaluated for collection of specimens for therapeutic drug assays and common clinical-chemical tests

The Monoject Samplette (Sherwood) capillary serum-separator tube was evaluated for use in pediatric capillary blood collection. When patients' values for eight common clinical-chemical tests and five therapeutic drugs were compared with values from specimens concomitantly collected in plain Caraway tubes, only chloride and total CO2 were significantly different. The chloride differences (range 0-2 mmol/L) were considered to be clinically insignificant. Higher CO2 values in Samplette specimens were apparently ascribable to decreased loss to the atmosphere. Samplette values for therapeutic drugs were higher than corresponding Caraway values, but only the differences for digoxin were judged to be clinically significant. Both recoverable serum and the incidence of hemolysis were lower in Samplette specimens than in Caraway specimens. Storage of serum over the clots (with separator material interposed) in Samplettes for 24 h had no clinically significant effect on results for glucose or potassium. Storage of specimens for as long as 24 h had no effect on theophylline, phenytoin, and gentamicin concentrations, but phenobarbital reproducibly decreased after 24 h. We conclude that the Samplette serum-separator tube is suitable for the collection of capillary blood for many of the chemical tests commonly ordered for pediatric patients.     

Effects of storage temperature and time before centrifugation on ionized calcium in blood collected in plain vacutainer tubes and silicone-separator (SST) tubes

We studied the stability of ionized calcium and pH in samples stored at either room temperature or 4 degrees C, in centrifuged and uncentrifuged blood-collection tubes and in centrifuged tubes containing a silicone-separator gel (SST tubes). At room temperature, in uncentrifuged blood from healthy individuals, mean ionized calcium usually increased no more than 10 mumol/L per hour; at 4 degrees C it did not change detectably for 70 h. This stability was fortuitous, however: the concentrations of both hydrogen and lactate ions in these samples increased, apparently with offsetting effects on the concentration of ionized calcium. Blood stored for 70 h at 4 degrees C in centrifuged SST tubes, although showing a slightly greater change in ionized calcium, had less change of pH and no change in the ionized calcium corrected to pH 7.4. In 11 heparinized whole-blood samples from eight patients in intensive care, the mean change per hour in ionized calcium and pH after storage at room temperature was +10 mumol/L and -0.04 units, respectively.     

塑料真空采血管对部分激素项目检测的影响

目的评价两厂家塑料真空采血管对部分激素项目检测结果及保存稳定性的影响。方法选取国内A、B两厂家生产的塑料促凝管分别保存30位健康体检者的血清,以玻璃无抗凝管作为对照,在3个时间（血清保存1h,保存24h以及保存48h）分别在雅培ARCHITECT i2000化学发光免疫分析仪上检测7项激素指标。结果在初始阶段,两厂家塑料采血管保存的血清与对照管相比各项目均无统计学差异（P〉0.05）。保存24h,与对照管比较,A管睾酮有统计学差异,但差异无临床意义,B管及A管其他项目与对照管比较无统计学差异。保存48h,与对照管比较,A管睾酮,促黄体生成素;B管孕酮,睾酮有统计学差异,但A管促黄体生成素和B管孕酮与对照管相比差异无临床意义,A、B两管睾酮差异均超出了临床可接受范围。结论两厂家塑料促凝管适合于激素项目的血液标本的采集和保存。