Biology/Physiology question

[Suikoden]

hey guys,

I am working on a project here and came across some figures that measure Fold Induction of a protein. I have tried to look on the web for precise explanation but I am only finding research articles that use that measure but don't really explain what it is.

So I was wondering if someone here would know. I know it measures activity of a protein, i.e. the higher the fold induction, the more activity there is. What I need to know though, is the mechanism behind it or how exactly does that measure work.

Thank you

[SDSD]

Fold induction is just a measure comparing expression/activity between proteins or other biological molecules (use it lots with mRNA) in a sample (in solution).

For example, you might see this in papers involving purification of a target protein from a specimen. In other words, as the sample gets more pure, the concentration of the target protein in a sample increases; its activity when quantified by any number of assays also increases.

So as the sample goes through multiple purification steps, its fold purification tends to rise. The fold purification is derived from that quantification of protein activity where the assay of activity of the initial sample is used as the base, and the fold purification for all further steps is calculated from that. If your experimental design calls for purification by protocols involving separation by fractionation, you may see a drop in fold purification relative directly attributed to discarded fractions.

So another direct use of the fold purification/induction number could be measuring the expression of a protein between different sample groups in an experiment; say a culture of cells engineered to doubly express a protein relative to a control culture. So then the fold induction values of the target protein for the experimental culture cells should be higher than the fold induction values for the control group. Also following from this type of experiment, if you were also measuring the target mRNA expression (rtPCR), the fold induction numbers for it would also be higher than the control group.

If you could post more info on your project I could probably give you a little more help but I think this should be enough general info to cover your question.

[Suikoden]

Yep, that works. Just wanted to have something to explain my data. Thank you very much for the reply.