Table 1.

Mechanical properties of degummed native and composite silk fibers

pnd-w1Spider 6Spider 6-GFP (line 1)Spider 6-GFP (line 4)Dragline (spider)
n = 11n = 11n = 10n = 19n = 7
AverageSDAverageSDAverageSDAverageSDAverageSD
Average diameters (μm)21.81.621.11.419.82.720.61.38.10.4
Mechanical properties
 Maximum stress (MPa)198.028.1315.365.8281.957.7338.487.0664.660.5
 Maximum strain (%)22.05.831.85.232.54.331.14.519.74.8
 Break stress (MPa)197.028.0314.565.6281.057.5336.387.3658.159.2
 Toughness (MJ/m3)32.010.071.713.968.916.277.229.579.625.4
 Young's modulus (MPa)3,705.0999.65,266.81,656.54,860.91,269.25,498.11,181.28,949.22,096.2
  • The mechanical properties of silk fibers produced by parental and transgenic silkworms were measured under precisely matched conditions. The average mechanical properties of spider (N. clavipes) dragline silk fibers determined in parallel are included for comparison. The table includes the numbers (n) of fibers tested in each group, isolated from cocoons spun by two (spider 6 and spider 6-GFP, line 4) or three (spider 6-GFP, line 1) individual animals.