Sample volume [Design Issues]

posted by Ohlbe – France, 2017-05-23 16:14 (2501 d 08:41 ago) – Posting: # 17396
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Dear nobody and Helmut,

❝ ❝ Isn't there an ethical/practical limit for blood sampling (from the top of my head I remember an absolute limit for blood volume to be taken within a trial...)?


❝ Yes there is. The total volume in the study should not exceed the one of a blood donation (if unavoidable, longer washout, measurement of HCT before later administrations, eventual exclusion of subjects…). But in the old days 10 mL / sample were taken and nowadays 5 mL are common.


Agreed. And I think this volume could easily be further reduced. Many labs still develop methods starting with 500 µl of plasma, just like in the old days of HPLC/UV, even though they are now using LC-MS/MS which can easily achieve an LLOQ several orders of magnitude lower. It would be perfectly feasible in most cases to only use 100 µl of plasma and reduce the blood sampling volume to 3 ml. This would still leave more than enough for repeat analysis and ISR.

Regards
Ohlbe

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