ABSTRACT. Blood samples are used as a biological source to discover biomarkers of hematological and non-hematological disorders. The present study shows the impact of different experimental conditions associated with cell lysis buffer, TRI-reagent protocol and blood cell storage buffer and their correlation with the quantity, quality and Adrenomedullin gene expression levels of total RNA when RT-PCR technique is used. A leukocyte cell bank protocol is also proposed for further mRNA expression analysis using RNAlater as storage buffer. There is evidence that total RNA isolated from leukocyte concentrate stored for 1 month at -70°C did not show significant differences concerning quality, purity and Adrenomedullin gene expression compared with the freshly processed leukocyte sample.

Key words: Leukocyte, RNA, RT-PCR, Adrenomedullin