Table 1.

Novel biofilm identification methods. Mechanism of diagnostic method, advantages, and disadvantages are summarized for each approach

Diagnostic method	Mechanism	Advantages	Disadvantages	References
Electron microscopy	Tissue biopsy processed and viewed under electron microscope, screen for microbial aggregates and EPS	Gold standard; high level of resolution; visualizes both surface and deep layers of biofilm	Requires invasive wound biopsy; detection limited to sampling location	[27, 28]
Fluorescent probe biomarkers in hydrogel	Fluorescent probe recognizes biofilm marker (e.g., alkaline phosphatase) and induces color change of hydrogel	Noninvasive; prompt detection with color change within 24 h	Probe recognition selectively limited to bacteria type or species; at proof-of-concept stage	[29]
Wound blotting with staining	Blotting the wound transfers biofilm to a nitrocellulose membrane; dyes stain the polysaccharides of biofilm EPS matrix: alcian blue > ruthenium red in sensitivity	Noninvasive; maps biofilm distribution on wound surface; rapid detection with visualization within 2 min	Staining set-up required	[30, 121]
Fluorescent imaging (MolecuLight i:X)	405 nm excitation light emitting diodes shone on wound; fluorescent image captured on device; host tissue appears green, bacteria at > 10^4 CFU/g appear red or cyan	Noncontact, handheld device; rapid detection with image at point of care	Does not distinguish between planktonic and biofilm bacteria	[31–33••, 122]