Some labs can perform free PSA measurements as low as 2 ng/mL.

“so we begin to use the kind of free PSAs and the free PSA ratios and all those things when PSAs have crossed over certain threshold right because yeah typically a lab if you if your PSA is one we can't even get a lab to check a free PSA that's that's right because we know if your P if you're screening someone and your PSA is one then the chances you the probability of a prostate cancer that's lethal is incredibly low right so that's why they they just don't they don't have the ass set up to check it and often times or some Labs will not that you know secondary default testing unless it's over four for example or over 2.5”