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Insulin Testing - Important Update


Eleanor Kellon, VMD
 

I asked Dr. Barbara Schanbacher from Cornell about sample type interference in assays and her reply is below:

"The assay used for this paper was the Immulite 1000 chemiluminescent insulin assay. This assay states it does not work on EDTA samples in the package insert. We do not use it because the assay curve has very poor sensitivity and about 15% of equine samples tested have wildly discordant results compared to the RIA we use. They are unfortunately stuck with this assay over in Australia and New Zealand as one of the better options because they can't get many of the assays available in the US.
 
Insulin is stable in serum and EDTA and heparin plasma in the RIA we use for 1 week on cells, 2 weeks in the fridge and > 5 years in the freezer and the results are comparable for all 3 sample types. "

So, unless the lab is using a CIA assay (Immulite most often mentioned in equine papers), there shouldn't be a problem at least with the Millipore brand assays used by Cornell, Guelph, Michigan State, BET Labs.  For other labs you will need to find out the type of assay being used.

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Eleanor in PA

www.drkellon.com 
EC Owner 2001


Rebecca and Joe
 

What about a Tosoh 360 AIA, test methodology is Fluorescence Enzyme Immunoassay. Is that a type of CIA? And if so if I'm understanding right are insulin results on that reliable as long as they are red or green top? Or would all results be innacurate?


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Rebecca and Joe,  Lexington KY, 2020

Case History: https://ecir.groups.io/g/CaseHistory/files/Rebecca%20and%20Joe


Eleanor Kellon, VMD
 

Those are different types of assays so I don't know the answer to your question. Also not sure if that assay has been validated for equine. It won't be affected by biotin though.
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Eleanor in PA

www.drkellon.com 
EC Owner 2001


riggslippert@...
 

Idexx says they use an RIA for equine insulin.  They couldn't tell me the brand without further investigation, but I can pursue if needed.
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Aunna
October 2018
Oakland County, Michigan, USA
Cadet Case History:  https://ecir.groups.io/g/CaseHistory/files/Aunna%20and%20Cadet
Ruger Case History:  https://ecir.groups.io/g/CaseHistory/files/Aunna%20and%20Ruger

Cadet Photo Album:  https://ecir.groups.io/g/CaseHistory/album?id=84102




Eleanor Kellon, VMD
 

 Honestly, I'm not sure if it matters but if you can get a name I can check a lot easier.
--
Eleanor in PA

www.drkellon.com 
EC Owner 2001