cut-off point and area under a complex line
 

Hi,

I am currently plotting the relative intensity of fluorescent markers to demonstrate where particular proteins are bein expressed across a cross-section of a single cell.

I have previously only used excel for data storage/simple graphs, and have no experience in using it to modify data/data analysis

I have 2 questions:
1. I would like to remove the "noise" from my data by introducing a cut-off point (i.e. everything under 250 on the y-axis = 0) can this be done simply, or will I have to manually subtract 250 from all data points?

2. I would like to calculate the area under the line for certain portions of a graph so different lines (protein expressions) can be compared. Is this something that excel is capable of?


Cheers in advance,

Ranui