Figure 3.

Assessing the limit of detection of protein chips using serial dilutions of Salmonella spp. Protein chips hybridised with serial dilutions of Salmonella cells after elution by thermal treatment of magnetic beads. Quantification of colony forming units performed in parallel by plating bacteria on XLD-Agar. Each sub-array was hybridised with a serial dilution of Salmonella, 10⁶ cfu/mL. (a) 10⁵ cfu/mL; (b), 10⁴cfu/mL; (c) 10³ cfu/mL; (d) and 100 cfu/mL; (e) Signals obtained by direct labelling of bacteria with Alexa 646. Experiments were repeated at least three times. Size of subarrays: 3 × 3 mm.