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Accueil > Départements > Microbiologie > Christophe SOLA : Infection Génétique Evolution des Pathogènes Emergents



The Beads4Med platform was created for the direct genotyping of bacteria of tuberculosis, salmonella and legionella’s diseases, thanks to the use of the technique of hybridization of magnetic/polystyrene microspheres with probes hybridizing the CRISPR loci of these bacterial species.

CRISPR typing : Generalities, and access to our services

The CRISPR locus (Clustured Regularly Interspersed Short Palindromic Repeats) is a genetic marker that allows identification and genotyping of many pathogenic bacteria. It was characterized at the RIVM (Netherlands) under the name of "Direct Repeat locus" in M. tuberculosis, the agent of tuberculosis. It was used to invent the "spoligotyping" technique which is described in our "spoligotyping" file. CRISPR loci are present in 100% of Archaea and 60% of bacteria and are constituted by a conserved sequence regions (the repeats) and variable sequences (the spacers). It plays still poorly known physiological roles, including anti-phage or anti-plasmid invasion defence. CRISPR typing allow to get a fine taxonomic characterization of bacterial species, both intra-specific and bio-geographic of clinical isolates, for molecular epidemiological or populations structure studies.


Three kits have been developed and are ready for use ; they are based on the coupling of specific probes amplified by PCR resulting from repeated sequences of CRISPR loci. The coupling of probes on the microspheres is a service offered to all customers who only require coupled microspheres.

Our dedicated team will help you to get your results, either by performing specialized Public Health/Research assays as indicated below and/or help you to develop cutomized, non-catalog microbead-based assays, either using protein or oligonucleotides (DNA or RNA-based assays on polystyrene or magnetic beads).

Assays run in routine on the Beads4Med platform :

- classical 43 spacers MTBC spoligotyping
- extended 68 spacers MTBC spoligotyping (for east Africa, India, South East Asia, East Asia)
- 3R SNPs assays (7-Plex)
- MTBC Spoligo-Rif-Typing (53-Plex)
- TB-SPRINT assays (59-Plex)
- Salmonella enterica Serovar typhimurium subtyping (72-Plex)
- Legionella pneumophila Sequence Type I pulsotype Paris *new in B4M*

Standard or Customized Beads coupling

The grafting of the probe to the microbeads is the heart of the activity of the platform.

Achieving couplings way is proposed for customers who send probes and microspheres.

Four combinations of microbeads / probes are ready : TB-SPOL, TB-SPRINT, STM-CRISPOL and the new one LP-SPOL, respectively for the typing of M. tuberculosis (43 and 68-Plex), typing and characterization of resistance of M. tuberculosis (59-Plex ), typing of S. enterica serovar Typhimurium (72-Plex) and typing of Legionella pneumophila (42-Plex).

The coupling of the microbeads is a simple protocol but which has many critical steps that can cause the failure of the manipulation performed.

The probes are grafted on the microbeads in series. Each probe is covalently bound to the microbeads by performing a covalent bond with EDC.

- upon request (ask for a quote)

in House or on Site Training

For the implementation of the techniques in your laboratory, training can also provided by our laboratory experts.

- upon request (ask for a quote)


Our first four available kits are :

- TB-SPOL, that supports the "spoligotyping" technique on Mycobacterium tuberculosis complex DNA by supplying specifically oligonucleotide-coupled microbeads and protocols

- TB-SPRINT, that supports the simultaneous spoligotyping and main Rifampin and Isoniazid SNPs characterization on Mycobacterium tuberculosis complex DNA to monitor and control Multi-Drug-Resistant Tuberculosis spreading by supplying specifically oligonucleotide-coupled microbeads and protocols

- STM-CRISPOL , that supports the Salmonella enterica serovar typhimurium subtyping using CRISPR genetic diversity to early detect potential outbreaks linked to this food-borne pathogen agent.

Curage intérieur : démolition des portes

- LP-SPOL, that support the "spoligotyping" on Legionella pneumophila Sequence Type I, pulsotype Paris by supplying specifically oligonucleotide-coupled microbeads and protocols

For more information, contact Christophe Sola

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