A wash step at collection of placental biopsies from preeclamptic pregnancies does not adversely affect levels of sFlt-1 or endoglin

•We assessed whether placental washing reduces sFlt1 and soluble endoglin.•Washing preeclamptic placenta did not decrease Flt-1, sFLt-1-e15a or sFlt-1-i13 mRNA.•Washing preeclamptic placenta did not decrease Flt-1 protein expression or localization.•Washing preeclamptic placenta did not decrease endoglin mRNA or protein localization.

There is recent interest for uniform placental collection protocols so laboratories can share samples. However, concerns have been raised a wash step at collection causes significant loss of sFlt-1 and soluble endoglin, among the most studied proteins in placentology. We measured Flt-1 and endoglin mRNA and protein in 10 preeclamptic placentas that were washed, or left unwashed. Reassuringly, there was no significant change in the Flt-1, sFlt-1-e15a or sFlt-1-i13 mRNA or Flt-1 or sFlt-1 protein expression or localization. There was also no change in endoglin mRNA expression or protein localization. Washing preeclamptic placental samples does not alter anti-angiogenic factor expression.