A pitiful amount of work for one day on SP-D during this lockdown….If I had a lab and a microscope and a little SARS Cov-2 virus and some SP-D you can be sure I would be looking closely (TEM or AFM, rotary shadowed, negative stained preps .. would not matter to me) anything would be wonderful.
But just say that in different sizes of SP-D found in so many different publications, yea, even different sizes in the same publication, I am relieved that my comparison measurements (3 measurements, diameter, and length of node (cusps) in each hexadecamer) are pretty close (The one tailed t-value is -0.30. The p-value is .38. The result is not significant at p < .05) (two tailed t-value is -0.30. The p-value is .77. The result is not significant at p < .05.) they are not that different… individual molecule measured at totally different times — that is a note for consistency. There were a couple exceptions in the published bar markers where they didn’t seem to fit, and certainly the cover image of Arroyo et al did not even come close to being the size reported for SP-D requiring a 74% (or so, check previous posts for exact amount) reduction in size. (140.01 + 10.4 and 137.51 + 4.7). Some relief in terms of the method. I predict there will be a significantly greater diameter when the actual diameter is used alone, (diameter touching at least three of the 4 CRD in a dodecamer) even though it is by far the easiest calculation, i don’t think it is the best.

By adding one more molecule measure 3 different methods, two separate times the p value looks like this (The t-value is -0.21974. The p-value is .830498. The result is not significant at p < .05.)