Single-use acupuncture needles: scanning electron-microscopy of needle-tips

Unselected, disposable acupuncture needles from various manufacturers and retail suppliers were taken from a pool of donated and bought samples. Three needles of each type were prepared for electron-microscopy. The needle tips were inspected at two magnifications (x39.37 and x612.5): 52 electron-micrographs were taken of 31 individual needles from 11 different types. No needle-tip looked perfect and significant faults were seen in most; some appeared seriously deformed. The faults noted were: scratch marks along or across the needle, metallic scuff, lumps and irregularities in the needle surface, needle-tip stubbed or malformed, and needle point off-centre. An additional test made was to wipe a number of needles firmly on white paper tissue. Some left grey lines, and these were regarded as evidence of metallic or oily residue from the needle surface which could have been deposited in the patient. These unexpected findings, in a variety of popularly used needles from well-respected suppliers, suggest that most manufacturers need to reassess their quality control procedures.