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Hi all,
When considering taking multiple samples from mice the main problem is
handling of the sample after it has been taken.
Does anyone have recommendations about taking small volume samples and
processing these (e.g. to plasma)?
When thinking about reducing current sampling techniques the problems
do not
arise when the sample is taken itself, but mainly how the sample is
taken
(syringe + needle, syringe + capillary, just a cappillary, special
collection device, etc). Afterwards the problems do continue, how is a
sample best processed for e.g. bio-analysis or blood consituents? Is
there a
problem with whole blood assays in comparison to plasma assays? Is it
pratically possible to obtain plasma from a 50 uL blood sample?
Has anyone got any recommendations or methods which may be of help?
Greetings,
Dennis de Mik, BSc Bio-Pharmaceutical Sciences Leiden University
MSc. student
Dennis de Mik
Johnson&Johnson Pharmaceutical Research&Development
a division of Janssen Pharmaceutica
Bio-Analyse (BAN) & Pre-Klinische Farmacokinetiek (PCPK)
* Turnhoutseweg 30 gebouw 017 lokaal 043
2340 Beerse
Belgium
* 0032 1460 5390 (bureel)
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Hello Dennis,Back to the Top
Though there are many ways for multiple blood sampling from mice. A
relatively easy method is retro-orbital puncture. You just need a mice
bleeding capillary for this procedure. 125 uL volume of blood can be
easily
collected by retro orbital pucture in a heparinized or EDTA containing
500
uL volume centrifuge tube. Centrifugation of the tube at around 6000 g
for 5
min provides approximately 50 uL of plasma.
Considerations should be given regarding the number of times you can
sample
a mice, for this a minimized sampling protocol can be employed. Were you
dose around 12 mice at a time (suited for per oral dosing studies, were
dose
administration is rapid and easier for dosing large number of
animals)and at
each sampling time, sample only three animals keeping one animal comman
between successive samplings, e.g. sample mice # 1,2,3 for first time
point
and mice # 3,4,5 for the second sampling time point and so on, taking
care
that none of the mice is sampled for more than two occasions in the
whole
study. Thus, minimizing the number of times you sample each animal.
Good luck for your studies.
Vijay V Upreti
Pharmacokinetics-Biopharmaceutics Laboratory
Department of Pharmaceutical Sciences
University of Maryland, School of Pharmacy
20 Penn St., Baltimore, MD 21201
Voice: 410-706-7388
Fax: 410-706-5017
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Hi Dennis
if you are taking about 50uL blood sample, i would personally feel it
would be wise to use whole blood assay rather than plasma. plasma would
be approx 40% of the total blood volume and in addition it would be
practically dificult to suck out a volume smaller than 50uL. you could
use whole blood unless there is an unusual partitioning of the drug
into the blood cells and there could be some amount of variability in
acheiving consistency in the recovery of the drug from the cells. Drug
partioning into the cells is totally another story.
Hope this might help u.
good luck
manish issar
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Drug Metabolism & Disposition, 32 (10), 1092, 2004 would be of help to
you for serial sampling in mice.
Sureb
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