I have the following dataset (triplicate values of 5 independent measurements and duplicate values of a control):
Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 C 181.8 58.2 288.9 273.2 290.9 53.9 120.3 116.8 108.9 281.3 446 39.6 86.1 148.5 52.9 126 150.3
The six conditions are independent production of a chemical in six different microorganisms.
My aim was to find if the production of the chemical is significantly higher in Samples 1 - 5 than in C (control).
At first, I carried out mean, SD and t-test (one-tail). Although SD error bars are large, two of the samples have mean values that are significantly higher than that of C.
I decided to carry out median and Wilcoxon-Mann-Whitney test because of my worry about the size of my data and the high variations in the replicates. I was surprised however, that median and Wilcoxon-Mann- Whitney tests did not reveal statistical significant results.
I will be happy if anyone could advise me on the best way to analyse this small dataset.