The effect of delay in collection and processing on RNA integrity in human placenta: experiences from rural Africa

Abstract

This paper examines the relationship between time to processing and RNA quality in placentas collected from women in a field setting in rural Gambia. Placental samples were collected from the villages and transferred to the laboratory. RNA was extracted using Trizol and integrity assessed using the RNA integrity number (RIN). Values were inversely correlated with delay in processing. Expression levels of candidate genes increased with decreasing RIN. Normalising to a housekeeper gene removed this artefact. We propose a cut-off point of 90 min from delivery, after which samples cannot be used for gene expression analysis.

Keywords: ENID; Iron metabolism; Placenta transferrin receptor; Placental genes; RNA; RNA integrity number (RIN); RT-PCR; Ribonucleic acid (RNA); TfR1; early nutrition and immune development; reverse transcription polymerase chain reaction; ribonucleic acid; transferrin receptor 1.