Fig. 2From: Duplicate analysis method: a cheaper alternative to commercial IQC materials in limited resource settings for monitoring CD4 testingRegression analysis of the CD4+ T cell counts in duplicate analysis method. Regression plots for duplicate analysis method plotted for samples with normal CD4+ T cell count (a), and low CD4+ T cell counts (b). Day 1 CD4 counts are plotted on X axis and day 2 CD4 counts are plotted on Y axis. Data from different laboratories are presented using different colours.Back to article page