The gels (4-20% polyacrylamide) were run for 48 hrs and stained with colloidal blue. A. Preformed POPC:apoA-I complexes at the 160:2 molar ratio were subjected to further incubation for 16 hrs at 4, 25, or 37°C without (-) (lane 1, 3, & 5) or with (+) (lane 2, 4, & 6) additional apoA-I to reach a final POPC:apoA-I ratio of 80:2. The results showed that the addition of apoA-I drove the formation of smaller particles with an increase of incubation temperature. B. Preformed POPC:apoA-I complexes at the 200:2 molar ratio were subjected to further incubation for 16 hrs at 4, 25, or 37°C without (-) (lane 1, 3, & 5) or with (+) (lane 2, 4, & 6) additional POPC in the form of MLV to reach a final POPC:apoA-I ratio of 400:2. The results showed that further incubations at increased temperatures sharpened the distribution of POPC:apoA-I assemblies in 16 hrs. but addition of POPC to preformed assemblies (predominantly R2-2) did not change the size distribution of these particles regardless of incubation temperatures C. Preformed R2-0 POPC:Δ43apoA-I particles at a 50:2 ratio and R2-2 POPC:apoA-I particles at a 160:2 ratio were incubated separately (lane 4-6 and lane 7-9) or together (lane 1-3) for an additional 16 hrs at 4, 25, or 37°C, respectively. The results showed that a new intermediate-sized particle (R2-1) (solid arrowhead) was formed at the highest incubation temperature.