To examine new cytochemical aspects of the bacterial adhesion, a strain 41452/01 of the oral commensalStreptococcus sanguisand a wild strain ofStaphylococcus aureuswere grown with and without sucrose supplementation for 6 days. Osmiumtetraoxyde (OsO4), uranyl acetate (UA), ruthenium red (RR), cupromeronic blue (CB) staining with critical electrolytic concentrations (CECs), and the tannic acid–metal salt technique (TAMST) were applied for electron microscopy. Cytochemically, only RR-positive fimbriae inS. sanguiswere visualized. By contrast, some types of fimbriae staining were observed inS. aureusglycocalyx: RR-positive, OsO4-positive, tannophilic and CB-positive with ceasing point at 0.3 M MgCl2. The CB staining with CEC, used for the first time for visualization of glycoproteins of bacterial glycocalyx, also reveals intacellular CB-positive substances—probably the monomeric molecules, that is, subunits forming the fimbriae via extracellular assembly. Thus, glycosylated components of the biofilm matrix can be reliably related to single cells. The visualization of intracellular components by CB with CEC enables clear distinction betweenS. aureusand other bacteria, which do not produce CB-positive substances. The small quantities of tannophilic substances found inS. aureusmakes the use of TAMST for the same purpose difficult. The present work protocol enables, for the first time, a partial cytochemical differentiation of the bacterial glycocalyx.