<p>Platelets are the smallest cells in the blood. They are formed in the bone-marrow and are important for the blood coagulation. Platelet tranfusions are given to patients propyhlactically before an operation but also in therapeutical purpose in connection with bleeding. It’s importent that the quality controls of the platelet concentrates are reliable.</p><p>ADVIA®60 (Bayer HealthCare) is a fully automated cell counter which uses impedance principle to count platelets in blood samples. The purpose of the study was to evaluate this new instrument for use in the blood bank of Akademiska Sjukhuset in Uppsala. The instrument was bought to be used for quality control of platelet concentrates. 30 samples from platelet concentrates, from both apheresis and from buffy coats, were analyzed 10 times each on ADVIA®60 and the coefficient of variation (CV) was calculated for each sample. CV variated from 0,8 % to 2,9 % which is good considering that according to Bayer HealthCare the CV should be < 5 % for thrombocytes on ADVIA®60. The instrument was newly calibrated when the study was performed. Platelet count can also be performed by immunological or optical principles.</p>

Platelets are the smallest cells in the blood. They are formed in the bone-marrow and are important for the blood coagulation. Platelet tranfusions are given to patients propyhlactically before an operation but also in therapeutical purpose in connection with bleeding. It’s importent that the quality controls of the platelet concentrates are reliable. ADVIA®60 (Bayer HealthCare) is a fully automated cell counter which uses impedance principle to count platelets in blood samples. The purpose of the study was to evaluate this new instrument for use in the blood bank of Akademiska Sjukhuset in Uppsala. The instrument was bought to be used for quality control of platelet concentrates. 30 samples from platelet concentrates, from both apheresis and from buffy coats, were analyzed 10 times each on ADVIA®60 and the coefficient of variation (CV) was calculated for each sample. CV variated from 0,8 % to 2,9 % which is good considering that according to Bayer HealthCare the CV should be &lt; 5 % for thrombocytes on ADVIA®60. The instrument was newly calibrated when the study was performed. Platelet count can also be performed by immunological or optical principles.

Biologiska toxicitetstester utförs genom att exponera en testorganism för olika koncentrationer av kemikalier under en bestämd period. Det finns akuta toxicitetstester och kroniska. Resultat från akuta studier presenteras som EC50-värde (Effect Concentration, affecting 50 % of the population). Tester som används som underlag för riskbedömningar ska utföras på kvalitetsmässigt acceptabelt sätt som grundas på International Organization for Standardization (ISO) och Good Labaratory Practice (GLP). Syftet med studien var att studera toxisk inverkan av kaliumdikromat på encellig sötvattenalg, R. subcapitata, genom att räkna cellantal med två olika instrument: flödescytometer och automatisk cellräknare. Vidare att jämföra testernas EC50 medelvärde mot ISO 8692 angivet värde i precisions syfte och att utvärdera de båda räknemetoderna gällande precision och analystid. Kaliumdikromat användes för tillväxtinhibering vid toxicitetstest. EC50-resultaten visade ingen statistiskt signifikant skillnad mellan de båda instrumenten (p=0,47). Den akuta toxicitetsanalysens precision kunde bekräftas som giltig då båda mätmetoders EC50 medelvärden vid jämförelse med ISO 8692 värde befanns inom bestämda 95% konfidensintervallet. Vid jämförelse av studiens två mätningsmetoder, observerades större spridning kring medelvärdet i cellräknarens resultat, där tre EC50 värden hamnade utanför 95% CI. Däremot visade resultatet från flödescytometern mindre spridning och högre noggrannhet jämfört med cellräknarens. Studien visade att flödescytometer skulle kunna användas i framtida toxikologiska tester med encelliga alger, men det krävs flera upprepade försök för att bekräfta fördelar med analysen i flödescytometern. / Biological toxicity tests are performed by exposing a test organism to different concentrations of chemicals over a certain period of time. Results from acute studies are presented as EC50 (Effect Concentration, affecting 50% of the population). Tests used as a basis for risk assessments shall be performed in a quality acceptable way based on the International Organization for Standardization (ISO) and Good Laboratory Practice (GLP). The aim of this study was to study the toxic effect of potassium dichromate on unicellular green algae R. subcapitata, by counting cells with two different apparatus: flow cytometer and automatic cell counter. Additionally, to compare the EC50 mean values against the ISO 8692 value for control of test precision and to compare accuracy and analytical time of two methods. Potassium dichromate was used for growth inhibition in toxicity tests. The EC50 results showed no statistically significant difference between the two instruments (p = 0.47). The accuracy of acute toxicity analysis was confirmed as valid as both EC50 average measurement values compared to ISO 8692 value were found within the 95% confidence interval. When comparing the two methods of the study, greater spread was observed around the mean value in the cell count's results, where three EC50 values were outside 95% CI. The result of the flow cytometer had less spread and higher accuracy compared to the cell count. The study showed that flow cytometers could be used in future toxicological tests with algae, but several repeated tests are required to confirm the benefits of analysis with the flow cytometer.

Allt mer forskning kring digitala bildanalysplattformar sker då de har visat lika bra eller bättre prestation än existerande manuella och automatiserade metoder samt effektiviserat handläggningstiden för patientprov. Nyligen har företaget CellaVision utvecklat ett prototypprogram som via bildanalys kan räkna och klassificera retikulocyter. Syftet med studien var att jämföra noggrannheten och precisionen av CellaVisions prototypprogram för retikulocytnumrering med manuell mikroskopering och en automatiserad cellräknare. Totalt 40 blodutstryk tillverkades av 20 blodprov med abnormala värden retikulocyter (&gt;2,5%) och 20 med normala värden retikulocyter (0,5-2,5%). Blodutstryken analyserades med prototypprogrammet, manuell mikroskopering och den automatiserade cellräknaren varpå retikulocytkoncentrationen för respektive resultat jämfördes med Pearsons korrelationstest och Bland-Altmananalys. Blodutstryk tillverkades av tre nivåer retikulocytkontroller och analyserades flertal gånger med prototypprogrammet vars retikulocytkoncentration jämfördes med andra metoders retikulocytkoncentrationer. Samma blodutstryk analyserades med olika antal inskannade celler för att utvärdera hur variationen påverkades. Resultaten från komparabilitetsstudien visade att prototypprogrammet erhöll en utmärkt korrelation och en god överensstämmelse med de andra metoderna. Precisionsstudien visade att prototypprogrammet erhöll konsekventa retikulocytkoncentrationer vid repeterade analyser och en låg variationskoefficient (0,25-10%) vid högre antal inskannade celler vid tre olika nivåer av retikulocytkontroller. Resultaten visar CellaVisions prototypprogram designat för retikulocyträkning erhåller en god noggrannhet och en hög precision vid jämförelse med manuell mikroskopering och en automatiserad cellräknare, dock behöver större studier utföras då antalet patientprov var begränsade. / More and more research on digital image analysis platforms is taking place as they have shown to have as good or better performance than existing manual and automated methods and have also streamlined the processing time for patient samples. Recently, the company CellaVision has developed a prototype program that can enumerate and classify reticulocytes via image analysis. The purpose of the study was to compare the accuracy and precision of CellaVision's prototype program for reticulocyte numbering with manual microscopy and an automated cell counter. A total of 40 blood smears were made from 20 blood samples with abnormal reticulocyte values (&gt;2,5%) and 20 with normal reticulocyte values (0,5-2,5%). The blood smears were analysed with the prototype program, manual microscopy, and the automated cell counter, after which the reticulocyte concentration for each result was compared with Pearson's correlation test and Bland-Altman analysis. Blood smears were made by three levels of reticulocyte controls and analysed several times with the prototype program whose reticulocyte concentration was compared with the other methods' reticulocyte concentrations. The same blood smears were analysed with different numbers of scanned cells to evaluate how the variation was affected. The results of the comparability study showed that the prototype program obtained an excellent correlation and a good agreement with the other methods. The precision study showed that the prototype program obtained consistent reticulocyte concentrations in repeated assays and a low coefficient of variation (0,25-10%) in higher numbers of scanned cells at three different levels of reticulocyte controls. The results showed the CellaVision's prototype program designed for reticulocyte counting obtained good accuracy and high precision when compared with manual microscopy and an automated cell counter, however, larger studies need to be performed as the number of patient samples was limited.