Hello!

I'm hoping to run an ELISA on human urine samples to measure testosterone levels. We are hoping to use a kit from Neogen, which has been validated for serum/tissue/urine. The protocol details testosterone extraction methods for serum, but notes that urine samples do not have to be extracted.

I must dilute my standards down in a medium that is similar to my samples, therefore, in this case, I would need to dilute my standards down in a known "negative" urine that is free of testosterone. Neogen says this is to reduce matrix effects by using mediums that have the same matrix interference. (In cases where I would do an extraction, I would extract with their buffers; therefore, I could dilute the standards in their buffers and still keep the same matrix interference).

Does anyone know of sources for this negative control urine? Or have experience with ELISAs with urine samples and could give tips on what they used to make their standards?

Thanks!!