Fig. 2.

Native gel electrophoresis of cryopreserved HDL. HDL isolated by density gradient ultracentrifugation was stored at −20°C or −70°C in the presence or absence of the cryoprotectants glycerol (10–50%) (A) or sucrose (2–10%) (B) for up to 100 weeks. Aliquots were analyzed at different time points and stained with Coomassie brilliant blue for protein or with Sudan black B for lipids. The dashed lines indicate the typical size range of HDL₂ and HDL₃ ranging from about 8 to 12 nm. To be able to illustrate structural changes of HDL upon long-term storage, we have placed the analyzed time points from each sample next to each other. Samples represent pooled HDL preparation from four healthy donors. Each storage experiment was repeated three times and results from one representative experiment are shown.