The purpose of this study was to examine whether variations occur in the % of motile micro-organisms on the dorsum of the tongue during a 1-month time-period and further to examine 2 transport fluids: the growth medium BM and reduced transport fluid (RTF), for their ability to conserve motility of microorganisms in comparison to sterile saline. Both transport fluids showed a significant reduction in the % of motile micro-organisms within 15 min. The use of RTF resulted, during a 60-min period, in a significantly higher % of motile micro-organisms compared to sterile saline. Results showed that the % of motile micro-organisms on the dorsum of the tongue was not constant. A significant reduction in the % of motile micro-organisms was observed in the course of the month involved in this study.