Ultrasonic imaging of biofilms utilizing echoes from the biofilm/air interface

The use of ultrasonic imaging to evaluate the effect of protozoan grazing and movement on the topography of bacterial biofilms

“…An 1-mm 2 area of biofilm, chosen randomly, was subjected to ultrasonic scanning. A full description of the method can be found in Holmes et al (2006) but in brief, the biofilm was scanned from beneath using a 50 MHz focused transducer. The surface of the biofilm was enclosed in as small a volume of moistened air as possible, to reduce evaporation.…”

“…Biofilm architecture is normally visualized and assessed in the laboratory using methods such as light microscopy, confocal scanning laser microscopy, direct interference contrast microscopy and atomic force microscopy. But another method which uses ultrasonic pulse‐echo scanning has recently been developed by the authors (Holmes et al . 2006).…”

“…Biofilm architecture is normally visualized and assessed in the laboratory using methods such as light microscopy, confocal scanning laser microscopy, direct interference contrast microscopy and atomic force microscopy. But another method which uses ultrasonic pulse-echo scanning has recently been developed by the authors (Holmes et al 2006). Ultrasonic techniques have long been used to nondestructively profile multilayer structures such as adhesives and paints on surfaces in situ (Challis et al 1991).…”

High frequency ultrasound imaging of a single-species biofilm

“…Holmes et al 23 imaged non-specific biofilms created in water ponds with a custom 50 MHz system. Placing an immersed transducer below a membrane and detecting reflections from an air/ biofilm interface allowed imaging the surface morphology of these biofilms.…”

Acoustic techniques to characterize food microstructure

“…In a scanning acoustic microsope a focussed ultrasound beam is coupled into the sample and the returning signal analyzed in a variety of ways, including simple pulse echo (Holmes, Laybourn-Parry et al 2006). The simplest implementation involves detection of a pulse reflected from an object (Fig.…”