We are planning to carry out differential proteomic analysis of cerebrospinal fluid from cryptococcal menigitis patients. What will be the statistically significant sample size for the experiment?
Olga Vitek has published extensively on this topic. One of the biggest factors is whether you just want to make a statement about your particular sample or whether you want to make a statement about all patients.
Your question is highly relevant. We work a lot with proteomics from clinical samples. We try to ensure we have at least 8-10 samples per group. We have even done studies which have upto 20 samples per group. In clinical proteomes, there is a high degree of inter-individual variability unlike in case of laboratory cultures. Therefore, go as high as your budget allows you. Study design is very important- have the right control groups. Then once you have your proteome profiles and have selected the proteins of interest, take the help of a biostatistician to estimate the sample size for statistically accurate validation.