Brain Research Protocols 10(2003):156-167
Methods To Optimize The Generation of cDNA From
Postmortem Human Brain Tissue
Christine L. Miller and Robert H. Yolken
The analysis of gene transcript levels in postmortem
human brain is a valuable tool for the study of neurological and psychiatric
diseases. Optimization of the methods of RNA extraction and cDNA
generation is particularly important in this application because postmortem
human brain tissue is in limited supply and generally yields less RNA than many
other human tissues. We compared column extraction and solvent extraction
for total RNA, reverse transcriptase (RT) with random hexamers versus oligo dT
priming, and incubation of the RNA with or without Dnase for effect on the cDNA
product derived from the same homogenized pool of postmortem human frontal
cortex. The total RNA obtained from the solvent method was found to be
less stable at room temperature and to contain a higher proportion of
non-messenger RNA than that obtained from the column method. Evaluating
the RT-PCR results per wet weight of tissue extracted, we found that the signal
strength was increased >20-fold by a protocol of Qiagen RNeasy column
extraction, random hexamer RT priming and omitting Dnase treatment of the RNA.