Work method
  The samples used for this research were taken from fresh corpses (deceased persons about 24 hours) in the Brest CHU morgue.
  On the acupuncture points LI 4, L 3, St 36, dermis samples measuring about 6 to 8 mm in diameter were used. All the samples were superficial. The deeper layers including the tendino-muscular system have never been studied. Some neutral points outside the meridians (about half of them) were also prepared for the sake of comparison with the acupuncture points.
After preservation in the Bouin solution, the samples were dyed :some with PERLS, others with HES and prepared on the usual histological slides.
For the first samples in 1990, a scalpel was used. Very few of the samples showed positive using the PERLS dye : out of the 30 samples in total (including 15 outside the meridians), 5 only showed positiv.
  In 1997/98, a cylindrical scalpel used in dermatology allowed the extraction of “carrot” shaped bits of dermis measuring from 5 to 8 mm in diameter, about 7 mm deep without the deep musculo-tendinous layer, which remains an essential part to study. The positive PERLS tests were numerous at the acupuncture points and negative on samples outside the meridians.
  Doctor Alain VOLANT, anatomo-pathologist at the Brest CHU compared the results according to the PERLS and HES dyes and by means of overlapping, he was able to show the following results.
  The PERLS dye : the Fe3O4 crystals appear as numerous scattered black dots on the usual histological sections.
The HES dye : the magnetite crystals show up in an amber orange yellow. They are difficult to spot out on the sections.
They could easily be mistaken for ARTEFACTS which would explain why many histological studies overlooked the magnetite crystals simply because they were not directly under investigation.
These crystals are to be found in the dermis around the sweat glands.
 

How does the microprobe work:

Through a high-speed beam of electrons, it irradiates a small surface (1 sq.micron) of the sample. A spectrometer is used for the analysis of the sample, in order to identify its different radiation features and in the process, assess the components which are to be found in this restricted volume (1 cubic micron). It is then possible to quantify the items of information comparing the characteristic x-ray intensities in each component to be found in the sample against a reference witness.
The analysis process and its use are monitored by a computer.
The results of the investigation are visualized, memorised and conditioned on video screen, printers, graph plotters etc.
The research results up-to-date (see slideshow) :

These results are of different types:
1/ the usual histological sections with the PERLS and the HES dyes
2/ direct photography via electronic microscopy with various enlargements.
3/component diagram after microprobe bombardment.
4/ photography via the microprobe.
5/percentage of the component findings after the microprobe bombardment.