A new method for the sampling and preservation of placental specimens in low-resource settings for the identification of P. falciparum and analysis of nucleic acids

J Histotechnol. 2022 Sep;45(3):116-119. doi: 10.1080/01478885.2022.2088191. Epub 2022 Jun 29.

Abstract

Collection, preservation, and shipment of histological specimens in low-resource settings is challenging. We present a novel method that achieved excellent preservation of placental specimens from rural Mali by using formalin fixation, ethanol dehydration, and long-term storage in a solar-powered freezer. Sample preservation success was 92%, permitting evaluation of current and past malaria infection, anemia, placental maturity, and inflammation. Using RNAscope® hybridization we were able to visualize cell-specific gene expression patterns in the formalin-fixed paraffin-embedded (FFPE) specimens. Additionally, our method entailed mirrored sampling from the two cut faces of a cotyledon, one for the FFPE workflows and the other for storage in RNAlater™ and RNA-seq.

Keywords: Field-work; RNA-seq; RNAscope®; histology; malaria; placenta.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Female
  • Formaldehyde / pharmacology
  • Humans
  • Nucleic Acids*
  • Paraffin Embedding
  • Placenta
  • Pregnancy
  • Tissue Fixation / methods

Substances

  • Nucleic Acids
  • Formaldehyde