Help me understand sample dilution in ELISA - (Feb/05/2019 )
Hello Orpheus,
First of all, when a method treats the sample and standards in the same way, there is no dilution factor. So, there is no reason to multiply by a factor the final result.
When a method uses a diluent, it is because there is a need to make the samples/standards more compatible with the method. Maybe it is due to the matrix effect or to form a better standard curve in terms of the range. This means that you do not use different volumes and then calculate the result with factors respectively. For instance, the only way to do this, is only if you add 10μl of the sample, 40μl of the standard 1 (in order to keep the appropriate matrix) and then 50μl of the diluent. In this case, indeed you have a dilution factor 5. However, the final volume must be 100μl because it is crucial for the reaction inside the well.
Sotirios
"First of all, when a method treats the sample and standards in the same way, there is no dilution factor. So, there is no reason to multiply by a factor the final result.
When a method uses a diluent, it is because there is a need to make the samples/standards more compatible with the method. Maybe it is due to the matrix effect or to form a better standard curve in terms of the range."
Okay, this part I can understand. The rest I'm not so sure of (I can understand the idea that the reaction must have 100 ul (all of them) as this intuitively makes sense). But I'm not sure I understand your example and also why you say 40 ul of STANDARD 1 (why would I mix sample and standard??).
Maybe you could explain it again another way?
Thanks a lot!