SMOLT platform for ultra-sensitive microbial detection in aqueous solutions

Overview

The SMOLT platform is an ultra-sensitive microbial detection system that identifies microorganisms in aqueous solutions at concentrations below 1 CFU/ml. Developed by Scanogen Inc., SMOLT (Single Molecule Tethering) leverages microbial ribosomal RNA as a detection target, exploiting its abundance within each cell and its rapid degradation outside viable organisms. This makes SMOLT particularly well-suited for detecting live microbes in medical and industrial aqueous samples, where rapid and accurate identification is critical for patient safety, product quality, and contamination control.

Unlike conventional diagnostics that rely on time-consuming culture-based methods or complex molecular amplification, SMOLT offers a streamlined, amplification-free workflow. The technology is designed to be integrated into a disposable cartridge paired with a compact, inexpensive instrument, enabling point-of-use deployment in clinical, pharmaceutical manufacturing, and water quality monitoring settings.

Technical specifications

How SMOLT works:

• Sample lysis using detergents and heat to release microbial RNA
• Hybridization of target RNA to DNA probes attached to micron-sized beads
• Detection of tethered beads in a capillary under fluid flow, where bead displacement serves as a digital signal indicating the presence of target nucleic acids

Key features and advantages:

• Ultra-sensitive detection with demonstrated limit-of-detection of 1-3 CFU/ml for major pathogens including P. aeruginosa, K. pneumonia, S. aureus, E. faecium, C. albicans, and C. glabrata in spiked whole blood
• Amplification-free workflow that eliminates the need for PCR or other pre-amplification steps
• Cost-effective cartridge estimated at approximately $3 per unit, including materials, labor, and equipment
• Simple protocol requiring no enzymes, fluorescence labeling, filtration, or centrifugation
• Low probe consumption with SMOLT probes used at concentrations below 1 nM
• Rapid results compared to multi-day blood culture methods
• Multiplexable design capable of classifying microorganisms into gram-positive bacteria, gram-negative bacteria, and fungi groups

Sample handling capability:

• Designed to analyze large aqueous samples (1-10 ml), enabling detection at very low organism concentrations
• Expected to perform better in aqueous solutions than in complex body fluids

Technology readiness level

The SMOLT platform has been validated through limit-of-detection studies using a semi-automated system with whole-blood samples spiked with six clinically relevant pathogens, achieving LODs ranging from 1 to 3 CFU/ml. An early version of the underlying tethering technology has been previously described in peer-reviewed literature.

Current development efforts are focused on creating a broad multiplex assay capable of detecting and classifying microorganisms across gram-positive bacteria, gram-negative bacteria, and fungi. Future validation will include testing the multiplex assay with a broad panel of organisms spiked in medical aqueous solutions, targeting an LOD of less than 1 CFU/ml for each organism. The team plans to integrate the full assay into a prototype disposable cartridge and evaluate its performance using a breadboard instrument, advancing the platform toward a commercially viable point-of-use diagnostic system.