TABLE 2.

Dimensions of mature and immature virions as determined by electron microscopy^a

WT or mutant prepn	Avg virus diam (nm) ± SD		Avg distance (nm) ± SD between two outer layers in immature particles	Avg core diam (nm) ± SD in mature viral particles
	Immature	Mature
G/GP	90.2 ± 18.2	85.9 ± 5.4	11.8 ± 2.4	31.9 ± 5.8
GCA2/GP	107.9 ± 18.8		13.9 ± 2.0
GCA6/GP	90.3 ± 16.4		11.9 ± 1.4
G/GPCA2	100.3 ± 9.4	109.6 ± 18.1	12.4 ± 1.8	36.2 ± 4.4
G/GPCA6	97.2 ± 6.4	99.8 ± 11.6	14 ± 0.5	33.3 ± 4.8

^aEach measurement is an average ± the standard deviation for four to seven particles.