You get a plasmid concentration of 0. Why did this happen?

When you blank the spectrometer with a substance, you are telling the spectrometer to ignore that substance. So, if you blank the spectrometer with plasmid, you are telling it to ignore the plasmid. This returns a value of zero.This does not tell us about the pGLO concentration or quality.

What else is present that you need to blank in the pGLO solution? Revisit Step 1.