I make dilution series to create standard curve (1000 pg/ml, 500, 250, 125, 62, 31, 15) but sometimes I apply in the reaction only 5 std.
I got std. curve with R^2 > 0.99 which is very good but still not enough, because I need almost perfect std. curve!
where R^2 = 0.999 or even 1.0, otherwise I'll get undetectable samples conc.! so I need to delete/ignore some std. point to reach 0.999 value, see the attachment.
I'm trying to delete only one point as much as possible using the software, but some times deletion two points (out of 5) is necessary especially the higher std. values.
My question is, is it ok if I delete 1000, 500 std. points while the sample conc. range between 0 - 250 pg/ml ? so the must important thing to get perfect linear curve within this range?
I confused & begin to wonder what are the rules to accept results!
what is the minimum acceptable R^2 value?
Is it acceptable to delete one or two std. points?
How can I choose the best parameters for fair results?!
When should I repeat the duplicated samples? what is the acceptable range of the mean?
Any help will be highly appreciated.
Thank you :)