NASA astronaut Reid Wiseman, storing experiments in the Minus Eighty Laboratory Freezer for International Space Station in the Japanese Kibo laboratory on the International Space Station.
Reid and ESA astronaut Alexander Gerst spent six months in space performing experiments and maintaining the Station.
Alexander Tweeted this image with the text: "Reid Wiseman (still with hair) inserting a blood sample for immune system research into an International Space Station freezer."
Follow Alexander via alexandergerst.esa.int.
Read more about his Blue Dot mission here.