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. 2021 Mar 27;11(4):283. doi: 10.3390/life11040283

Figure 6.

Figure 6

Viability of yeast cells stored chilled or frozen. At the conclusion of the growth period during the mission, cells were chilled to 4 °C (A) Micro-6 and (B) Micro-14/FPA. Alternatively, cells were frozen at <−80 °C and transported to Earth at <−25 °C with (C) glycerol as a cryopreservation agent in Micro-14/FEP, Large FEP bags or (D) without glycerol in Micro-14/FEP, Small FEP bags. Following sample return and hardware de-integration, cells were immediately isolated, counted, diluted, and plated to quantify colony formation. Colonies were counted after 3 days of growth at 30 °C. Data is represented as the actual number of colonies relative to that expected based on cell counts. Panel A represents samples activated late in the mission (Late) with either the high inoculum (High) or low inoculum (Low), as previously described. Black bars = flight; green bars = terrestrial controls. * p < 0.03, ** p = 0.003, flight vs. terrestrial.