Biofilm loss during sample preparation for scanning electron microscopy

Biofilm morphology and mass are two of the important characteristics governing the kinetics of substrate removal by biofilms. Many previous studies showed only sparse biofilm on attaching media. However, one of the reasons which might cause a sparse-biofilm specimen in scanning electron microscopy (SEM) is that the treatment of a biofilm sample is harsh and can cause various artifacts. This study was conducted to evaluate the loss of biofilm during a conventional preparation procedure. Biofilm lost during preparation stages was collected on membrane filters. A different technique-the membrane filter method-was devised to carry a biofilm sample through the preparation stage with reduced losses. The sample was sandwiched between membrane filters during preparation so that the loss was minimized and the lost biofilm could be saved for qualitative and quantitative evaluations. SEM examination of biofilms and membrane filters showed that biofilm loss was much more significant with conventional treatment.