Primary fixation included: 2.5 % glutaraldehyde, 2% formaldehyde in 0.1 M Na-phosphate buffer, pH 7.4. Post-fixed in 2% OSO4 in 0.1 M Na-phosphate buffer, pH 7.4. Stained en bloc in 1% uranyl acetate.
Method A: wet-bulk volume measured with special volume sampler; method B: wet-bulk volume measured by gas pycnometry; method C: dry volume measured by gas pycnometry
