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Irukulla Shravan Kumar ★ India, 2013-03-18 08:02 (4851 d 07:56 ago) Posting: # 10214 Views: 4,921 |
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Dear, what should be the general acceptable temperature limits for centrifugation of the bio samples. generally we perform the centrifugation at 4C. why need to follow at this temperature only. kindly provide the relevant reference documents if any Regards, I.Shravan |
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ElMaestro ★★★ Denmark, 2013-03-18 15:51 (4851 d 00:07 ago) @ Irukulla Shravan Kumar Posting: # 10224 Views: 4,237 |
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Hi Irukulla Shravan ❝ what should be the general acceptable temperature limits for centrifugation of the bio samples. generally we perform the centrifugation at 4C. why need to follow at this temperature only. ❝ kindly provide the relevant reference documents if any There is to the best of my knowledge no reference doc. By way of thermodynamics it is most often so that most degradation processes or other undesired chemical processes happen to be slower at lower temperatures. That's one argument for processing cold. At the end of the day your assay (incl. sampling, storage, processing, injection and all) should be tailored to the specific API so this isn't just about tradition and general thermodynamics. If you for some reason gain some relevant advantages by spinning at 16, 26 or 86 degrees C then by all means do that. — Pass or fail! ElMaestro |
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Helmut ★★★   Vienna, Austria, 2013-03-18 17:46 (4850 d 22:12 ago) @ ElMaestro Posting: # 10225 Views: 4,200 |
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Hi Irukulla & ElMaestro! ❝ ❝ generally we perform the centrifugation at 4C. You mean this is the temperature you set. Depending on the manufacturer/model/placement of the sensor the actual temperature will be something different. The temperature in the vials is not accessible at all. ❝ If you for some reason gain some relevant advantages by spinning at 16, 26 or 86 degrees C then by all means do that. 86?  Even at 26 ℃ you can expect a pretty mess (a smelly clot) unless you centrifuge very small volumes.In my old CRO we set the temperature to –4 ℃. The actual temperature at the end of the cycle (20 minutes at 2000×g) was ~ 2–4 ℃. No freezing, but the increased viscosity allowed separation of plasma by simple decantation – faster than pipetting. But you are are right – whatever works and is validated is fine. — Dif-tor heh smusma 🖖🏼 Довге життя Україна! ![[image]](https://static.bebac.at/pics/Blue_and_yellow_ribbon_UA.png) Helmut Schütz ![[image]](https://static.bebac.at/img/CC by.png) The quality of responses received is directly proportional to the quality of the question asked. 🚮 Science Quotes |
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Ken Peh ★ Malaysia, 2013-03-18 18:45 (4850 d 21:13 ago) @ Helmut Posting: # 10227 Views: 4,252 |
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Hi Irukulla, ElMaestro and Helmut, We have been spinning the plasma samples at air-conditioned room (about 24C) with basic centrifuge with no temperature control. So far, we do not face any problems of drug degradation in plasma. We spin at 3500-4000 rpm for 15 min for 5 mL of plasma. I believe many labs spin at -4C for the prevention of drug degradation (in case). Regards, Ken |
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Ohlbe ★★★ France, 2013-03-18 19:44 (4850 d 20:13 ago) @ Ken Peh Posting: # 10229 Views: 4,286 |
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Dear Ken, ❝ So far, we do not face any problems of drug degradation in plasma. I think the issue is not just degradation in plasma but in whole blood. I would expect the lower temperature to decrease the activity of the various erythrocyte enzymes. As the whole blood stability is usually not studied, most labs prefer to spin in a refrigerated centrifuge to limit the risk of degradation of the analyte and metabolites. Anyway, I agree with the previous posts: there is no temperature specified in the FDA and EMA guidelines (I don't know about others), just use whatever works / is needed. regards Ohlbe — Regards Ohlbe |
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Helmut ★★★ Vienna, Austria, 2013-03-19 00:14 (4850 d 15:43 ago) @ Ken Peh Posting: # 10230 Views: 4,221 |
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Hi Ken, ❝ […] We spin at 3500-4000 rpm for 15 min for 5 mL of plasma. See this post (and the other one linked within) for rpm vs. gravitational force. Unless you state the diameter of the rotor rpm is meaningless. — Dif-tor heh smusma 🖖🏼 Довге життя Україна! Helmut Schütz The quality of responses received is directly proportional to the quality of the question asked. 🚮 Science Quotes |
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Irukulla Shravan Kumar ★ India, 2013-03-19 06:00 (4850 d 09:57 ago) @ Helmut Posting: # 10232 Views: 4,146 |
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thanking you all for providing such a good information on the centrifugation timings. Regards, I.Shravan |
Ing. Helmut Schütz