Hi all,   This is my first time here. Could you please help me on how to best analyze my data?   I started off with 30 animals and we took blood samples for hour 0 (pre-toxin exposure; baseline) and killed 6 of them for organ collection. At hour 3 (post-toxin exposure), I had 24 animals for blood collection and another 6 killed for organ collection. At hour 6 (post-toxin exposure), I had 18 animals for blood collection and another 6 killed for organ collection. At hour 12 (post-toxin exposure), I had 12 animals for blood collection and another 6 killed for organ collection. At hour 24 (post-toxin exposure), I had 6 animals left for blood and organ collection. All animals had the same treatment.  The goal was to see the effect of the toxin exposed in time series.   How could I analyze my data on blood collection? This is not a repeated measure because I lost 6 animals in each time period (if it is please give me a bit of advice).  I could think of trend analysis as you can see from the code I have here. For pairwise comparison, is it acceptable to do when each hour did not have the same animals (6 animals less)?     Thank you very much for your suggestions.     Proc glm data =A1; class hour; Model BW = hour; Lsmeans hour / stderr CL Lines pdiff adjust=tukey ; Contrast "Linear" hour -0.474342 -0.316228 -0.158114 0.1581139 0.7905694; Contrast "Quadratic" hour 0.5459642 0.0352235 -0.334623 -0.651635 0.4050702; Contrast "Cubic or LoF" hour -0.469987 0.4222581 0.5143463 -0.570498 0.10388; run; quit;   ... View more