Comparison of the needles used in the preliminary testing. The upper needle is the usual stainless steel needle. The lower needle is the one made of gold. Both needle types made by Shenzhou, China. The size of the needles was: 25 × 0.25 mm for the stainless steel needle and 40 × 0.13 mm for the gold needle.
Moncayo et al. BMC Medical Imaging 2007 7:4 doi:10.1186/1471-2342-7-4