六联采血袋制备浓缩血小板制剂的质量分析

目的比较2种采血袋制备手工浓缩血小板制剂的质量。方法分别用四联采血袋和六联采血袋各采集400 mL全血30袋,白膜法制备浓缩血小板,并评价血小板质量相关指标。结果六联袋制备的浓缩血小板质量:容积为(37.97±5.70)mL/2 U、Plt计数为(8.06±1.41)×1010个/2 U、RBC混入量为(2.64±0.83)×109个/2U,其他多项生化指标均较四联袋略好;四联袋所制浓缩血小板的质量:体积为(45.60±4.32)mL/2 U,Plt计数为(5.63±2.04)×1010个/2 U,RBC混入量为(4.73±2.37)×109个/2 U,2组相比差异具统计学意义(P<0.05)。结论六联袋制备手工浓缩血小板质量优于现有四联袋分离系统,值得推广应用。     

全血室温过夜制备浓缩血小板制剂的质量分析

目的探讨全血室温过夜后所制备的浓缩血小板制剂(PC)的质量。方法对12份400 ml新鲜全血采用无菌接驳机平均分为2份,采用白膜法制备PC,1份当天制备(对照组),1份室温过夜后制备(实验组),分析该2组所制PC剂的数量和功能。结果对PC质量体外评估发现,2组Plt无统计学意义,血小板数均符合国家标准(≥2.0×1010个/U),对照组为(2.78±1.49)×1010个/U,实验组为(3.49±1.19)×1010个/U,实验组血小板数明显高出对照组20.3%。实验组CD62表达、乳酸产生、pH、PCO2和K+含量明显高于对照组。实验组PO2含量则低于对照组,其他检测指标在2组间无明显变化。结论全血置室温过夜有望成为手工制备PC优选模式。     

医用电解质溶液作添加液制备汇集少白细胞血小板

目的采用医用电解质溶液作添加液(PAS),建立1种白膜法制备添加液汇集少白细胞血小板(PAS汇集BC-PCs)的方法。方法从400ml全血中分离白膜层,容量35—40ml,放(22±2)℃静置过夜,将ABO同型的6袋白膜汇集,加220g添加液(90%复方电解质注射液、8%ACD-A血液保养液和2%含量为50g/L的碳酸氢钠注射液的混合液)稀释白膜,汇集后的白膜在(22±2)℃中,以300×g离心10min,将上层的富含血小板悬液再经白细胞滤除器过滤去除白细胞,并转移到血小板保存袋内,即制备成1个成人治疗量的PAS汇集BC-PCs,制备过程在一个特制的密闭系统内完成。结果共制备30个成人治疗量的PAS汇集BC-PCs,其容量为(270±32)ml、血小板含量为(2.96±0.31)×1011、WBC混入量为(1.3±0.2)×106、RBC混入量为(5.8±1.1)×109、CD62P表达率为(22.5±10.6)%。保存8d后的pH为7.14±0.04、低渗休克反应率(HSR)为(54.0±8.2)%、CD62P表达率为(45.7±13.8)%。结论由复方电解质注射液、ACD-A保养液和碳酸氢钠注射液的混合液为添加液汇集血小板的方法可行。     

血小板添加液延长血小板保存期的研究

目的探讨血小板浓缩液(PC)加入血小板添加液延时贮存后的质量。方法将新鲜全血(400ml/袋)在4—6h内分离出的白膜层(BC)于22℃静置过夜,取同血型的7袋BCs汇集制备成PC后滤白,用血小板添加液(PAS-ⅢM+血浆)贮存21d,并在存储期内分时间段测定其血小板含量、红细胞和白细胞残留量、最大聚集率、CD41和CD62p阳性表达率、代谢产物和pH值等。结果血小板含量≥2.5×1011/袋,WBC残留量≤3.0×105/袋;贮存至d10,其pH值维持在7.00左右,CD62p阳性表达率45%,ADP和肾上腺素合用诱导的聚集反应率为15%—88%,凝血酶诱导的聚集反应率为89%—99%,HSR恢复率为41%—69%。10d内有可供血小板代谢需要的葡萄糖,乳酸盐浓度随着葡萄糖含量降低而升高,PO2随着PCO2降低而增加。结论加入PAS-ⅢM+血浆的PC贮存10d仍含有可供血小板正常代谢的能量物质,具有较好的聚集功能和抗低渗休克反应的能力。     

全血于22℃保存24h分离制备悬浮红细胞及浓缩血小板的质量评价

目的 评价全血于22℃保存24 h分离制备悬浮红细胞及浓缩血小板的质量.方法 采用简单随机抽样法选择2014年5月至2015年2月广东省茂名市中心血站招募的60例献血者为研究对象.研究对象纳入标准:所有献血者献血前体检及相关血液学检查结果符合《献血者健康检查要求》(GB18467-2011)的相关规定.将60例献血者随机分为2组,每组各30例.两组献血者均分别采用五联采血袋采集全血各400mL,共计60袋全血.研究组献血者全血置于22℃保存和运输,并于采血后24 h制备悬浮红细胞和浓缩血小板.对照组献血者全血于22℃保存和运输,并于采血后8h内制备悬浮红细胞和浓缩血小板.两组献血者全血均采用白膜法制备悬浮红细胞和浓缩血小板.悬浮红细胞4℃保存至储存期末(制备后35 d),采用Bact/ALERT全自动微生物检测系统对其进行无菌试验;并比较两组悬浮红细胞的红细胞计数、血细胞比容(HCT)、血红蛋白(Hb)水平、游离血红蛋白(FHb)水平、储存期末溶血率,以及K+、Na+、C1-浓度.浓缩血小板22℃保存至储存期末(制备后5 d),采用Bact/ALERT全自动微生物检测系统对其进行无菌试验;并比较两组浓缩血小板的血小板含量、红细胞混入量、FHb水平、储存期末pH值、黏附率、聚集率及K+、Na+、C1浓度.结果 ①研究组与对照组悬浮红细胞储存35 d后,均无细菌生长;两组浓缩血小板储存5d后,均无细菌生长;②研究组与对照组悬浮红细胞储存35 d后,其血细胞比容(HCT)、血红蛋白(Hb)水平、储存期末溶血率均符合《全血及成分血质量要求》(GB18469-2012)的相关规定;两组悬浮红细胞的红细胞计数、HCT、Hb水平、FHb水平、储存期末溶血率及K+、Na+、Cl-浓度比较,差异均无统计学意义(t=0.55、0.51、1.18、0.48、0.72、2.86、2.07、2.40,P＞0.05);③两组浓缩血小板储存5d后,其血小板含量、红细胞混入量、储存期末pH值均符合《全血及成分血质量要求》(GB18469-2012)的相关规定;两组浓缩血小板的血小板含量、红细胞混入量、FHb水平、血小板黏附率、血小板聚集率,储存期末pH值,以及K+、Na+、Cl-浓度比较,差异均无统计学意义(t=0.17、0.16、0.56、2.43、0.36、2.50、1.85、1.75、0.32,P＞0.05).结论 22℃保存24 h制备的悬浮红细胞、浓缩血小板的质量符合国家标准,全血22℃保存过夜分离制备悬浮红细胞、浓缩血小板的方法可行.     

洗涤混合血小板的质量和部分体外功能的测定

目的了解混合白膜层(BC)法制备的洗涤混合血小板(洗涤混合BC-PC)的质量和体外功能,为临床应用提供质量依据。方法400ml/袋新鲜全血在4~6h内分离出的BC在22℃静置过夜,6袋同血型的BCs混合、制备成BC-PC,用生理盐水洗涤,用血细胞计数仪测定该洗涤混合BC-PC的血小板含量和红细胞残留量、用Nageotte白细胞计数板测定白细胞残留量、用比浊法测定最大聚集率、用流式细胞计数仪测定CD41和CD62p阳性表达率,并测定该制品的pH值和血浆蛋白清除率。结果血小板含量≥2.5×1011/袋,白细胞的残留量达到106/袋,血浆蛋白清除率≥98%,胶原蛋白诱导的最大聚集率>90%,CD62p阳性表达率平均为19.52%。结论生理盐水洗涤混合BP-PCs的质量符合单采血小板和洗涤红细胞的标准,具有较好的聚集功能,洗涤并未加强血小板的活化,可以用于临床输注。     

全血采集后即时制备与贮存过夜后制备的浓缩血小板质量比较

目的评价不同储存模式制备的浓缩血小板的质量。方法 2018年7—8月随机抽取60名献血者,分别采用六联采血袋采集全血400 mL/人(袋),均分为即时(制备)组:采集的全血置22℃保存和运输,并于采血后6 h分离制备浓缩血小板;过夜(制备)组:采集的全血于22℃保存、运输并过夜贮存,采血后24 h分离制备去白悬浮红细胞及浓缩血小板;2组均采用白膜法制备浓缩血小板。取2组浓缩血小板的标本作细菌培养及血细胞计数,比较血小板含量、容量及混入红细胞、白细胞的量。同时比较2组血小板代谢及功能性指标:血小板聚集率(%)、HSR、CD62p阳性表达率以及pH值。结果对即时组和过夜组的60袋浓缩血小板的标本进行细菌培养,结果显示:需氧菌与厌氧菌均为阴性,均无细菌生长。即时组和过夜组2组浓缩血小板质量控制项目结果,均符合《全血及成分血质量要求》(GBl8469-2012)的相关规定。2组浓缩血小板的血小板含量及白细胞混入量比较,差异无统计学意义(P0.05),红细胞混入量和浓缩血小板的容量比较,差异有统计学意义(P0.05)。2组血小板体外功能指标检测结果显示,血小板聚集率、HSR、CD62p表达率及pH值差异均无统计学意义。结论全血即时分离制备与全血过夜分离制备的浓缩血小板功能性指标及活化程度相近,均符合国标要求。结合本站工作实际,采用即时法制备浓缩血小板符合本站的制备状况,我们须充分利用各种设备,确保血液制备的安全、有效。     

2种国产白细胞滤器过滤混合浓缩血小板后的功能比较

目的 对比2种国产白细胞滤器对浓缩血小板的滤除效果及过滤前后浓缩血小板质量的变化.方法 采用白膜法以400 mL新鲜全血制备浓缩血小板,将8袋ABO同型的浓缩血小板汇集(50～60 mL/袋),分别用A、B2种国产血小板滤器对血小板进行过滤,每组各30例(50～ 60 mL/例).检测过滤前后Plt、RBC和WBC计数、PDW、MPV、pH值、血小板膜表面CD62p表达率、血小板聚集和低渗休克,计算白细胞清除率和血小板回收率.结果 过滤后A、B2组Plt、RBC计数、PDW、MPV、血小板膜表面CD62p表达率、血小板低渗性休克和WBC清除率均无统计学差异(P＞0.05);白细胞残留量达到了质量标准.过滤后A、B2组pH值分别为7.23和6.81、血小板回收率分别为84.4％和75.7％、血小板聚集率分别为18.92％和5.08％,均有统计学差异(P＜0.05).结论 2种白细胞滤器均可有效去除血小板中的白细胞,过滤后的血小板基本符合血液质量要求.A组滤器过滤后较B组能保持更高的血小板回收率及血小板的功能.     

不同方法制备的浓缩血小板表面CD62分子的表达

目的　了解不同制备方法对浓缩血小板表面CD6 2表达的影响。方法　采用藻红素标记的抗CD6 2单抗 ,经流式细胞仪分析血小板表面CD6 2表达情况。结果　 (6 .5 5± 3.5 2 ) %的机采血小板表达CD6 2 ,(9.2 6± 5 .4 0 ) %的白膜回浆法 (BC法 )血小板表达CD6 2 ,高达 (5 0 .30± 2 0 .4 2 ) %的富血小板血浆法 (PRP)血小板表达CD6 2。结论　相对于PRP法 ,机采法和BC法更适合于浓缩血小板的制备。     

白膜法汇集浓缩血小板体外质量和功能特性研究

目的研究白膜法汇集浓缩血小板体外质量和功能特性,为国家制定统一的白膜法血小板质量标准提供依据。方法应用白膜法制备汇集浓缩血小板并检测分析各项质量指标,与机采血小板国家标准(GB18469-2001)比对。分别用血小板聚集仪和流式细胞仪测定白膜法汇集浓缩血小板、机采血小板对诱导剂ADP的最大聚集率与血小板膜表面糖蛋白分子CD62P和PAC-1的表达率。结果白膜法制备的汇集浓缩血小板质量指标分别为:容积为(270±14)m l,含量为(2.58±0.51)×1011,pH值为7.24±0.09,红细胞混入量为(6.61±0.16)×109,白细胞混入量为(0.011±0.008)×109。两组血小板对ADP的最大聚集率分别为(85.1±9.0)%和(87.9±11.1)%,P>0.05;两组血小板膜表面糖蛋白分子CD62P表达率分别为(12.3±1.7)%和(11.7±2.1)%,P>0.05;PAC-1表达率分别为(9.3±1.7)%和(8.9±1.4)%,P>0.05。结论白膜法汇集浓缩血小板体外质量指标均达到机采血小板国家标准,血小板功能活性保持良好。     

Comparative analysis of platelet concentrates prepared after two hours and overnight storage of buffy coat at room temperature

IntroductionThe overnight storage of the buffy coat (BC) at room temperature has logistic and operational advantages for the blood centre. The present study aimed to evaluate the impact of an overnight hold (stored) of BC at room temperature in comparison with the 2-hour hold (fresh) of buffy coats on the platelet concentrate (PC) characteristics.MethodsA total of 60 BCs were included in the study, 30 PCs (fresh) were prepared after two hours holding time of the BCs and the other 30 PCs (stored) were prepared after the overnight BC storage at room temperature. The primary endpoint of PCs evaluation was the platelet yield, volume, pH, WBC count, RBC count, and platelet swirling in the PC and the secondary endpoints were glucose concentration, lactate, LDH, and sterility of the PCs. All the tests were performed on the day+1 of the blood collection.ResultsThere was no difference concerning the volume, RBC count, and swirling between the two groups (P>0.05). The PCs from the fresh BC had higher pH and glucose concentration (P<0.05). On the other hand, the overnight hold of BC produced higher platelet counts, WBC counts, lactate, and LDH levels (P<0.05). All the 60 PCs did not record any bacterial growth on the culture media for the sterility results.ConclusionThe overnight hold of BC produces a higher platelet yield with higher storage lesions. This may also allow better supervision, ensuring better quality control.     

Donor platelet and leukocyte count as predictive factors of the quality of platelet concentrates obtained from whole blood by semiautomated fractionation

Platelet concentrates (PCs) obtained from whole blood are produced by fractionation of the buffy coat (BC) or the platelet-rich plasma. Despite the improvements in the technologies used for the hemocomponent fractionation, the proportion of PCs that do not accomplish the quality requirements is high. This study aimed to determine whether the basal platelet and leukocyte counts are predictive factors of the quality of the PCs obtained from BC by semiautomated fractionation. Quality control registers of 196 PCs were analyzed. Gender- and age-dependence of the blood cell count and the characteristics of PCs were evaluated. Platelet yield and residual leukocytes in the PCs were correlated with the platelet and leukocyte counts and the age of the donors. Predictive efficacy was assessed, and an optimal cut-off was established. The proportions of PCs accepted and rejected by using or not the optimal cut-off were compared. 50.0% of the PCs accomplished all the quality control requirements. Female donors had a higher basal platelet count than males. A correlation was observed between basal platelets and platelet yield, but not between basal leukocytes and residual leukocytes. The basal platelet count predicted the quality of the PCs. A cut-off of 231,000 platelets/mm³ was established, but it did not improve the proportion of accepted PCs. In conclusion, we found that the basal platelet count is correlated with the platelet yield. The basal leukocyte count is not correlated with the residual leukocytes. The established cut-off for the basal platelet count did not improve the proportion of accepted PCs.     

WBC content of platelet concentrates prepared by the buffy coat method using different processing procedures and storage solutions

BACKGROUND: The number of WBCs in platelet concentrates (PCs) prepared by the buffy coat (BC) method with different storage solutions can result in low (5 x 10(6)/unit) WBC levels by the use of careful centrifugation techniques without filtration. At present, most blood banks use filtration steps to meet these requirements. The difference in processing methods and suspension solutions prompted the investigation of the influence of the various procedures on the WBC and platelet content of PCs. STUDY DESIGN AND METHODS: PCs from 5 BCs were harvested without or with inline filtration (AutoStop BC, Pall Corp.) in either plasma (PCs-plasma) or platelet additive solution (PCs-PAS-2). After preparation, samples were taken for counting WBCs and platelets and for analyzing WBC subsets by flow cytometry using specific MoAbs. The WBCs were concentrated before analysis of the WBC subsets. Results less than 2.5 cells per microL were considered below the limit of accuracy of the subset analysis. RESULTS: All filtered PCs met the AABB standard of 5 x 10(6) per unit and the European guidelines of 1 x 10(6) per unit. None of the nonfiltered PCs met the European guidelines, but all met the AABB guidelines. All filtered units gave residual WBC counts below the detection limit for subset analysis. Filtered PCs-plasma gave significantly higher platelet counts than filtered PCs-PAS-2 or nonfiltered PCs (p<0.01, ANOVA). CONCLUSION: Careful centrifugation of pooled BCs, with plasma or PAS-2, can result in PCs with low WBC contamination levels. However, filtered PCs are superior, because of better WBC removal and higher platelet counts.     

全血手工制备浓缩血小板后的血浆再制备冷沉淀的质量评价

目的评价室温新鲜全血白膜法制备浓缩血小板后的血浆再制备冷沉淀的质量。方法实验组为24例,新鲜全血(400 mL)置室温于<8 h用白膜法制备浓缩血小板后所得的血浆,冰冻保存。对照组1为12例,常规制备新鲜冰冻血浆,冰冻保存。对照组2为12例,新鲜冰冻单采血浆,血浆单采完毕分装为200 mL/袋并立即冰冻保存。3组血浆按常规制备冷沉淀,评价其质量:外观、凝血因子FⅧ及Fib的含量;血细胞残留量。结果 3组冷沉淀外观均正常;WBC含量在3组间无统计学意义。与对照组1比较:实验组凝血因子FⅧ(81.76±34.07)IU较低,Fib(202.63±48.58)mg及Plt(7.81±5.81)×109均较高。与对照组2比较:实验组凝血因子FⅧ含量相当,Fib(202.63±48.58)mg较高、Plt(7.81±5.81)×109较低。结论全血来源的制备浓缩血小板后的冰冻血浆还可以用于冷沉淀的制备,其质量符合国家标准。     

The effect of interruption of agitation on in vitro measures of platelet concentrates in additive solution

BACKGROUND: Interruption of agitation results in lower in vitro quality of platelet concentrates (PCs). The rates at which the deleterious effects occur, however, are unknown. Therefore, in vitro parameters of PCs in additive solution (AS) during various periods without agitation have been investigated. STUDY DESIGN AND METHODS: PCs from five buffy coats in AS (Composol, Fresenius HemoCare) were white cell (WBC)-reduced by filtration. Four PCs were pooled and divided to obtain paired samples. Beginning immediately after processing, three PCs were stored without agitation and placed on an agitator after 16, 20, and 24 hours. The fourth PC was agitated throughout storage and served as reference (n = 10 paired experiments). RESULTS: pH(37 degrees C) on Day 7 was greater than 6.8 in reference PCs, and in PCs that were not agitated for 16 hours, longer interruption resulted in lower pH values. During interruption of agitation, metabolic rates were significantly higher in the study groups: glucose consumption was 12.5 +/- 1.6 micromol per 10(11) platelets (PLTs) per hour in PCs during the first 24 hours without interruption versus 2.0 +/- 0.4 micromol per 10(11) PLTs per hour in the reference group (p < 0.01). Lactate formation was 24.7 +/- 4.2 versus 3.9 +/- 0.4 micromol per 10(11) PLTs per hour in the above-mentioned groups, respectively (p < 0.01). Once replaced on the agitator, the metabolic rates lowered, but remained significantly elevated during consecutive storage days compared to the reference. CONCLUSION: WBC-reduced PCs in Composol AS may experience 16 hours without agitation with no permanent effects on in vitro measures compared to reference units. During interruption of agitation, glucose and lactate metabolism is elevated, resulting in lower pH values in the subsequent storage period.     

A prospective randomized study of three types of platelet concentrates in patients with haematological malignancy: corrected platelet count increments and frequency of nonhaemolytic febrile transfusion reactions

We prospectively randomized 51 patients with haematological malignancy requiring platelet concentrates (PCs) to receive either single donor plateletpheresis products (SD-PC), PCs made from pooled buffy coats (BC-PC) or pooled units of platelets made by the platelet-rich plasma method (PRP-PC). The leucocyte content of each type of PC was 0.33 (0.03–13.5), 5.68 (0.19–99.0) and 365 (65–910) × 10⁶; median (range), respectively; P  < 0.0001. All red cell transfusions were leucodepleted by filtration. Statistical comparison of the probability of the occurrence of a nonhaemolytic febrile transfusion reaction (NHFTR) following transfusion of PCs in patients in each group showed a significant decrease for the SD-PC and BC-PC groups (0.031 and 0.038, respectively) when compared with PRP-PC (0.171); P  =0.001. The actual corrected platelet count increments (CCI) at 1–6 and 18–24 h post-transfusion for all three types of PC did not differ significantly. We conclude that transfusion of PRP-PC is associated with a significant increase in NHFTR.     

The effect of different agitation modes on platelet metabolism, thromboxane formation, and alpha-granular release during platelet storage

Platelet concentrates (PCs), prepared by plateletpheresis, were stored in aliquots in polyvinylchloride blood bags for 5 days at 22 degrees C under rapid, slow, or no agitation. Nonagitated PCs were also stored in a 98-percent oxygen atmosphere. In nonagitated PCs, pO2, lactate production, and platelet factor 4 (PF 4) concentration increased, whereas the ATP level and pH dropped rapidly. These changes were somewhat minimized in nonagitated PCs stored in oxygen. There was no significant difference between the two agitated groups. The increase in PF 4 correlated inversely to the decrease in ATP: r = -0.91, p less than 0.001, n = 24. The formation of thromboxane B2 (TxB2) after stimulation with arachidonic acid or collagen was significantly higher in slowly agitated PCs on Day 5 than on Day 0 (p less than 0.01). Nonagitated PCs produced lower levels of TxB2 (collagen stimulation) on Day 5 (p less than 0.05). In unstimulated PCs, the levels of TxB2 and ATP were inversely correlated on Day 5 (r = -0.70, p less than 0.001, n = 20). In vivo survival was performed after 72 hours of storage; mean survival (+/- SD) was 6.5 (+/- 0.3) days for nonagitated oxygenated PCs and 6.8 (+/- 0.7) days for agitated PCs. In nonagitated PCs, anaerobic metabolism increased, although oxygen diffusion through the container wall was sufficient. Agitation seems to facilitate the diffusion of oxygen through the storage medium. Nonagitated PCs were stored safely for 24 hours; this period can be extended to at least 72 hours when aerobic metabolism is maintained.     

In-process cell counts during preparation of platelet concentrates from buffy coats

To ensure the quality of platelet concentrates (PCs), we studied in-process recoveries of blood cell counts in pooled PCs derived from four or five buffy coats (BCs) from Biopack Compoflex Systems in Bern (PC-BC/4 or PC-BC/5) and from five BCs from Optipac (Baxter) in Zurich (PC-BC/5). BCs were pooled employing a sterile connecting device and flushing them with 300 mL of platelet additive solution. The pools were centrifuged for 12 min at 500 g at 20 degrees C and filtered with PALL's Auto-Stop BC-leukocyte removal filter. Automated platelet counting was performed on whole blood donation, on single BC, on pooled BC and in the final product. Four out of 10 PC-BC/4 (= 40%) and 29 out of 30 PC-BC/5 (= 97%) had a total platelet count of > 200 x 10(9) platelets. Average percentage recoveries in PC compared to the pre-centrifugation BC pools were similar with the Biopack Compoflex and the Optipac systems, 62% and 57% respectively, whereby the absolute platelet count per one donation was similar, i.e. 49.5 x 10(9), 55 x 10(9) and 53 x 10(9) in PC-BC/4 and PC-BC/5 from Bern and PC-BC/5 from Zurich. There was a significant positive correlation between the inital number of BCs taken for pooling and the final platelet counts in the PCs. In order to recover a minimal platelet content of 200 x 10(9) platelets per pooled unit, it is safer to start out with five rather than with four donations unless recoveries during the production steps can be improved.     

Noninvasive pH measurement to monitor changes during suboptimal storage of platelet concentrates

BACKGROUND: Noninvasive pH measurement of platelet concentrates (PCs) was evaluated as a tool for the quality control of PC storage by simulating worst‐case conditions. STUDY DESIGN AND METHODS: PCs from pooling four buffy coats in 70% PAS‐3M were both stored in bags wrapped to impair gas permeability and agitated or not until Day 9 of storage. pH values measured both in samples (electrode, blood gas analyzer) and noninvasively by fluorimetry (BCSI pH1000, Blood Cell Storage, Inc.) were compared groupwise and to changes in platelet (PLT) size and biochemical variables. RESULTS: The noninvasive pH measurements agreed well with the results from each of the two reference methods (R² > 0.9) in a wide range of pH values between 6.4 and 7.5. Changes of the pH of PCs (n = 64) by all interventions (agitation or resting plus occlusion by 0, 25, 50, or 100%; n = 8/group) were subtle but already significant after 20 to 24 hours of treatment in comparison to the controls. A steady state after Day 6 and reductions up to a mean pH of approximately 6.5 were observed. The extent of manipulation determined both the absolute pH differences to the controls and the interindividual variation of pH changes. Termination of the agitation significantly enhanced pH reduction by surface blockade. Significant changes were also observed for the mean PLT volume, β‐thromboglobulin, and soluble P‐selectin. CONCLUSION: Noninvasive pH measurement in PCs using this technique reliably detects pH changes of 0.1 or more. Storage of PLTs in buffered additive solution requires profound impairment of gas exchange to trigger a substantial decline in pH.