Figure 2From: Reverse genetics through random mutagenesis in Histoplasma capsulatumGradual freezing in DMSO maximizes recovery of cryopreserved Histoplasma yeast. WU15 yeast were frozen in varying concentrations of glycerol (A) or DMSO (B). Histoplasma yeast were grown to late log/early stationary phase in rich medium and added to the appropriate glycerol- or DMSO-containing solutions before freezing. Final cryoprotectant concentrations indicated along the x-axis of each graph. Vials were placed immediately at -80°C (rapid freeze) or were placed into a styrofoam container before placement at -80°C (slow freeze). Frozen cell aliquots were thawed after 1 week or 9 weeks and recovery measured as the number of viable cfu relative to the number present before freezing.Back to article page