Expression of HSPD1 'tracking' the sustained productivity phenotype: 2D-DIGE and western blot analysis to demonstrate HSPD1 protein expression 'tracking' the sustained productivity phenotype in the SQp and NSQp cell lines from Cell Line Pairs A and B. A. Graphical representation of 2D-DIGE gel protein spots showing the standardized log abundance of spot intensities at days 3, 7 and 10 from DeCyder analysis of (i) Cell Line Pair A and (ii) Cell Line Pair B. Blue data points - 'SQp' samples; red data points - 'NSQp' samples. B. Western blot analysis of HSPD1 protein expression in the two cell line pairs, A and B. GAPDH was used to demonstrate equal loading between samples.