This text isn't written very well: peak height refers to the maximum value of whatever is being measured, whereas titre is an example of a measured variable. The limit of detection is the lowest concentration, titre or whatever which can be measured (i.e. determined to be statistically different from the background value); in other words, it is the lowest peak height which can be recognised as a peak.
peak titre
- Thread starter kapa18
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pontios
Well-known member
By reciprocal relationship I meant a multiplicative inverse relationship for each particular peak titre sample and its corresponding LOD titre pair.
So let's say starting with a particular peak titre sample in which its LOD titre has been determined to be reached after 6 serial dilutions (6x two-fold dilutions ) .. the LOD titre (or the assay cut off titre - το όριο ανίχνευσης) in this example would have 2^(-6) or 1/64th the level of concentration of its peak titre.
So a multiplicative inverse relationship exists - but I've digressed a little, I just found this an interesting topic.
So let's say starting with a particular peak titre sample in which its LOD titre has been determined to be reached after 6 serial dilutions (6x two-fold dilutions ) .. the LOD titre (or the assay cut off titre - το όριο ανίχνευσης) in this example would have 2^(-6) or 1/64th the level of concentration of its peak titre.
So a multiplicative inverse relationship exists - but I've digressed a little, I just found this an interesting topic.
As far as I know, the LOD is provided by the manufacturer and is known precisely, so you can't say that there's a relationship between the two since the LOD is a constant. What you mean is that you can use one to determine the other in some cases (e.g. a qualitative method with serial dilutions, as you describe).
It is indeed an interesting topic
It is indeed an interesting topic
pontios
Well-known member
I think we're on the same page. :mellow:
The way I figure it(I could be wrong) ..is
A laboratory may have predetermined a LOD concentration for a particular analyte (an assay concentration cutoff which is a constant as you say for the particular analyte concerned - but let's say it happens to be an 1/80th of the peak titre sample we're currently analysing - and i realise that the peak titre concentration can vary from instance to instance, as the antibody response itself is a variable - dependent on the vaccine being tested and dosages etc..). .
The laboratory can then nevertheless work to an exact LOD titre - a slightly higher concentration where the level of confidence in a laboratory test result would be even higher... back from the 1/80th to 1/64th or the 6th dilution.
If the LOD is an exact titre .. then there would be a reciprocal relationship based on the titre count.
The way I figure it(I could be wrong) ..is
A laboratory may have predetermined a LOD concentration for a particular analyte (an assay concentration cutoff which is a constant as you say for the particular analyte concerned - but let's say it happens to be an 1/80th of the peak titre sample we're currently analysing - and i realise that the peak titre concentration can vary from instance to instance, as the antibody response itself is a variable - dependent on the vaccine being tested and dosages etc..). .
The laboratory can then nevertheless work to an exact LOD titre - a slightly higher concentration where the level of confidence in a laboratory test result would be even higher... back from the 1/80th to 1/64th or the 6th dilution.
If the LOD is an exact titre .. then there would be a reciprocal relationship based on the titre count.