peptide quantification in plasma by ELISA - (Nov/18/2006 )

Hi all,

We have a high sensitivity elisa kit to determine a peptide in plasma samples. As a negative control, I took plasma samples from a deficient mouse for this specific peptide. I still can detect low levels of the peptide in the plasma and peritoneal fluids of the deficient mouse. Does anyone have experience with this kind of controls?
PS, we do extract the peptide from the plasma before the ELISA determination
Thanks in advance

When you extract the peptide, what solution is it in when you put it on the plate?

We redisolve the extracted peptide in the assay buffer of the ELISA kit

since you use a high sensitivity kit, u are going to find minute amounts of the peptide in your " deficient sample"...this is normal

but how do you know your sample is peptide-free?