Plasma from AIDS patients were quantitated for the presence of HIV RNA by QA-PCR and also by the microchip method. The plot on the left represents the data from 86 patients whose viral copy numbers varied from 100 to 75,000 viral copies per 0.1 ml of plasma.

The plot on the right shows the extended view of the data for samples with viral copies between 100 and 10,000 per 0.1 ml of plasma