# Virus Packing

- The capsid is spherical.
- dsDNA is a 2 nm diameter cylinder of length 340 nm * N, where N is the number of kilo- base pairs (kbp) in the genome.
- dsRNA is a 2 nm diameter cylinder of length 270 nm * N, where N is the number of kilo- base pairs.
- ssDNA is a 1.4 nm diameter cylinder of length 340 nm * N, where N is the number of kilo-bases (very inaccurate!)
- ssRNA is a 1.4 nm diameter cylinder of length 270 nm * N, where N is the number of kilo-bases (very inaccurate!)
- For the interstrand spacing, the strands are hexagonally packed.
- I calculated radius of gyration as sqrt(
*Lp*), with*p*taken as 50, 60, 1.5, and 1.5, repsectively.

Notice the huge range of packing efficiencies! High packing efficiency may imply a highly pressurized capsid. Many of the numbers I used are rough outer diameters - an inner diameter, when available, will give you a better estimate of the pressure.

For information on our experiments to measure the pressure in viruses,
contact Paul, grayson@caltech.edu,
or see our group webpage: `http://www.rpgroup.caltech.edu/`

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