Standard Curve - Why does the blank have an OD value? - (Jun/10/2010 )

I have a couple of questions regarding ELISA standards. Is the curve supposed to be of sigmoidal shape? and the blank at 0 has an OD value of 0.1 - is that normal?

For the second part of your question- yes it is normal for the blank to have an absorbance reading. This is your background absorbance (ie absorbance of your blank solution) and should be subtracted from each of your test values.

generally ELISA does not essentially follow the beer lamberts law... so they best curve to use to analyze a ELISA is the 4 PL graph!!