Methods: A standardised cell suspension of Candida albicans GDH 2346 was prepared to an OD of 1.0 at 540nm and diluted to 104 (102 cells/100µl ± 2) in PBS. 70µl of this suspension was inoculated into a perfusion chamber (CoverWell, Grace-BioLab) with a glass cover slip and a Concanavalin A coating. This inoculated set up was secured onto a heated (37¢ªc) stage of an optical tweezer microscope (Ku Life, Denmark). Using laser light, individual cells were picked up and manoeuvred to a ‘clear zone’ on the substratum (no cells in a 2 field circumference) where they were allowed to adhere (>10 secs). Cells were placed at different distances from one another. The chamber was subsequently flooded with 50% horse serum, sealed with adhesive tabs (Invitrogen, USA) and incubated for 2-3 hours. Images were captured every 2-10mins. In total, 12 experiments were run.
Results: In 17% of cases hyphae grew away from each other: - in 33%, they grew towards one another, and in 50% the behaviour was deemed to be random.
Conclusions: These results suggested there was no overall pattern in hyphal responses. Gas chromatography analysis of growing Candida cultures revealed the evolution of volatile compounds (ethanol and farnesol) over time. These are known to influence hyphal and biofilm growth and their effects on directional hyphal development will be explored further.