The oligomerization of influenza a virus matrix 1 (m1) protein was analyzed using affinity chromatography followed by gel filtration. (a) purified recombinant m1 (with a c-terminal his6-tag) from nickel affinity chromatography eluted in peak 4. the fraction containing peak 4 (from panel a) was collected. sds-page analysis determined that the peak 4 fraction was 100% pure. (b) half of the collected fraction was applied to a superdex 200 hr 10/30 gel filtration column at ph 7.4 (physiological ph). (c) half of the collected fraction was applied to a superdex 200 hr 10/30 gel filtration column at ph 5.0.