Blake is characterizing the phages that he has discovered further,

ladder    apo    A    B    C    D    E1    E2    HI    J30

The BAM HI cuts, below, will be done again with a higher concentration of DNA. 

Blake's recommendations: do a test run to first determine how much DNA you have before digesting and running a gel to it's fullest.  Using this methodology, take a small amount of phage DNA and load it onto a gel.  Run at a high voltage, i.e. 100 V, to see if