Table 3.
Direct and indirect biofilm detection and enumeration methods for food processing settings.
| Test | Type | Method | References |
|---|---|---|---|
| Direct | |||
| BioFinder | Qualitative | Direct observation of color change due to dying of biofilm components. | [62] |
| Contact plates | Quantitative | Sterile agar plate is placed on surface of interest and biofilm is detected via conventional culture methods. | [67] |
| Direct epifluorescence microscopy | Quantitative | Automatic cell quantification using computer software on digital images. | [68] |
| REALCO Biofilm Detection Kit | Qualitative | Direct observation of color change due to dying of biofilm components. | [63] |
| TBF® 300/ TBF® 300S | Qualitative | Direct observation of color change due to dying of biofilm components. | [64] |
| Indirect | |||
| BacTrac 4300 | Quantitative | Total viable counts calculated via impedance. | [69,70] |
| Plate count | Quantitative | Culture plating to determine the number of colony forming units (CFU). | [57] |
| TEMPO® | Quantitative | Cell counts from biofilms are calculated using most probable number (MPN) system based on fluorescence. | [65] |
| Abcam XTT tetrazolium salt and resazurin assay kit | Quantitative | Metabolic assays combined with spectrophotometry can be used to quantify biofilm. | [57,71,72] |