Since everyone is using different 1st Abs to this antigen and different 2nd Abs, the histograms by OD450 do not provide much information. If there is a common reference (standard) preparation from the same supplier that everyone is using, it would be good to express all your data relative to this standard. If not, you need to calculate and provide the titer of your antibody used, and give exact definition for the term "titer" in your experiments and procedures of the antibody generation/purification/characterization, if you developed the Ab in your lab. If this is a commercial 1st Ab you just need to indicate the company Cat # and the dilution you used. 

you can use curve for presentation 

U can try representing Absorbance values of both control and treated in box plots. 

Hello Manoj,

Coverting OD values to antibody concentration is a time taking process and most of the people don't take that headache. Best way to represent an ELISA result is to report exact concentration as calculated against some standard by using OD values. That will represent the true difference. Sometimes, OD values can be confusing. e.g. 0.25 and 0.27 OD may look similar and may not give statistical significance but in concentration terms one may be representing some 1000ng/ml of antibody/protein and other may be representing some 1200ng/ml of protein. So in this case, bar diagram will truly represent the difference and a good statistical comparison can be drawn. So please, try to express it in final concentration in your diagram instead of OD values..

Hope it helps !