The size and shape of native alpha crystallin aggregates extracted at either 4°C (α-crystallin) or 37°C (αm-crystallin), were compared with each other, as well as with aggregates reconstituted from either pureαA orαB subunits using electron microscopy. TheαB aggregates were the most uniform in size (about 9 nm in diameter) and the best stained.αA particles were about the same size as theαB, but the population distribution was broader and some indication of interparticle association was observed.αcparticles exhibited a bimodal distribution, with one peak greater than the reconstituted particles and the other about the same size;αmwas smaller than the reconstituted structures.