In addition, for a subset of brain samples (for each type of brain tissue) we used the geometric mean of SYP and ENO2 and the GAPDH as normalization controls and confirmed the selection of SYP as a representative normalization control for the entire brain set.
For cytoplasmic and nuclear fractionation, four brain samples for each age and genotype were prepared as described earlier [ 42].
For cytoplasmic and nuclear fractionation, four brain samples for each genotype were prepared as described earlier [ 19].
For insolubility assessment, four brain samples for each age and genotype underwent sequential extraction in buffers of increasing stringency, based on a modified protocol previously described [ 43].
This value, Ct, or cycle number at threshold, was used for calculations of relative abundance of mRNA molecules in the liver samples compared to the brain samples for each of the amplification methods.
An arbitrary significance level of 0.01 was chosen from the linear regression results to establish these 2 lists (this differed from the brain sample for which a threshold of 0.05 was set due to the number of genes exceeding significance in lymphocytes and a 2000 gene limit set by the DAVID web tool).
Dr. Kari Stefansson, a neurologist and DeCode's chief executive, noted it was extremely hard to get enough schizophrenic brain samples for good statistical analysis but, given that constraint, the new finding was promising and "remarkable if true".
However Bauer et al. (2003), demonstrated in their study a significant correlation between RNA degradation and PMI in stored refrigerated human brain samples for up to 5 days.
We consistently observed small numbers of TUNEL-positive cells throughout the brain samples for all ages.
We would like also to thank Dr. Randy Woltjer, Dr. Kathleen Hayden, Dr. Lauren Warren, Mari Szymanski, and John Ervin for their assistance in obtaining the required brain samples for the study.
