Western Blot - Analysis of Experimental Data

You wish to explore the expression pattern of the POI protein  in various tissues of the centaurembryo. (POI - Protein of Interest - is a fictional protein, used as an example in this tutorial.) Your goal is to determine whether the horse-derived organs and the human derived organs differ in the expression pattern of POI.
To that end you take a 30 days embryo, dissect the various organs, prepare whole tissue lysates from the various organs and run samples in two equal polyacrylamide gels, taking special care to load equal amounts of the lysates in each well. You use one gel to prepare the blot, and treat it with an anti-POI antibody, and then with a secondary antibody  conjugated to a reporter enzyme. Immunoblotting will show you only the POI protein on the gel.
You use the second gel to perform Coomassie staining. This staining will show ALL proteins on the gel.

Here are the results of the two procedures.

Coomassie Staining 
(Detects all proteins)
Immunoblot
(Detects the POI protein)
What can you learn about the expression pattern of POI?
1. Immunoblotting is not sensitive enough. We can see POI in all samples following Coomassie staining but not following the immunoblotting. Apparently, Coomassie staining is a more sensitive method.
2. Something went wrong with the immunoblotting. Thus, we hardly see any staining. We need to repeat the procedure more carefully.
3. There are relatively low amounts of POI in the various organs, so we cannot detect them using whole tissue lysates.