In this example, progression of HIV antibody development can be seen from left to right.   Each column is a separate Western blot result taken from a newly infected person over a 30-day period.  The first two on the left are the negative (NC) and positive controls (PC).

 

Each black or dark grey horizontal stripe is representative of the presence of a different antibody against a protein found in HIV. To be conclusive (HIV-positive), a Western Blot must have 5 horizontal stripes.

The Western Blot