The high aggregate stability of Andosols and the direct effects of sample drying led to several inconsistencies during physical soil organic matter fractionation. We have determined that NaCl addition displayed little influence on clay dispersion. At the microscale, we observed the re-aggregation of the clay fraction caused by freeze-drying. This issue was avoided by analyzing aliquots of soil suspension. Thus, we recommend reserving a small soil liquid aliquot to be subjected to microscopy analysis.