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- Posts: 77
- Joined: Thu Sep 22, 2011 5:02 pm
Hi guys,
I have a question about sampling low volumes of murine plasma. We basically collect the blood retroorbitally from the mice, then we do a protein precipitaton followed by a solid phase extraction using about 25uL of plasma.
My question is for the pharmacokinetic assessment on the early time points, I am assuming a large amount of compound X and when we sample at later time points the concentration will diminish rapidly.
If the curve and assay is built for 25uL of plasma, should i use only about 5uL of plasma and bring it to volume for the early on time points basically diluting it 5X.
I have not performed this assay and I have no idea what to expect after dosing. Our curve range is from about 25ng/mL-2,000ng/mL, I am assuming in the later time points the 25uL of plasma will be just fine , but am not sure how to handle the dilution of the early on time points?
Basically I want all the samples to fit in the curve, but I think this is almost impossible by guessing.
Our dose will be given IV at around 10mg/kg in nude mice.
Does anybody have experience with PK sampling of rodents using LC-MS-MS?, How do you guys do it?
Any ideas, tips or tricks would be great?
I have a question about sampling low volumes of murine plasma. We basically collect the blood retroorbitally from the mice, then we do a protein precipitaton followed by a solid phase extraction using about 25uL of plasma.
My question is for the pharmacokinetic assessment on the early time points, I am assuming a large amount of compound X and when we sample at later time points the concentration will diminish rapidly.
If the curve and assay is built for 25uL of plasma, should i use only about 5uL of plasma and bring it to volume for the early on time points basically diluting it 5X.
I have not performed this assay and I have no idea what to expect after dosing. Our curve range is from about 25ng/mL-2,000ng/mL, I am assuming in the later time points the 25uL of plasma will be just fine , but am not sure how to handle the dilution of the early on time points?
Basically I want all the samples to fit in the curve, but I think this is almost impossible by guessing.
Our dose will be given IV at around 10mg/kg in nude mice.
Does anybody have experience with PK sampling of rodents using LC-MS-MS?, How do you guys do it?
Any ideas, tips or tricks would be great?
