Paired t-test for leucocyte counts before (aliquot 0 as reference) and after unfreezing with and without DMSO

Leucocyte countNMean (× 109/L)SD
Observer 13013.1410.67
Observer 1/DMSO+3010.20*7.74
Observer 1/DMSO−305.50**6.10
Observer 2226.73*4.10
Observer 2/DMSO+223.19**2.69
Observer 2/DMSO−221.8711.27

N: number; SD: standard deviation. P < 0.01, P < 0.001