Maxwell Sensors Inc. has combined two advanced technologies, lithographic digital barcodes and molecular chemistry, to create its new, patented Digital Magnetic Beads (DMB) technology, a breakthrough designed to significantly improve the isolation and identification capacity of molecular diagnostics. MSI’s digital microbead (100-300 µm) has the highest multiplexed barcodes (5 - 1,024) in the world. Maxwell Sensors Inc. has span-off Digital Magnetic Beads technology to Applied BioCode, Inc., which was formed to commercialize the multiplex Digital Magnetic Beads for molecular diagnostics and life science applications.

 

 

Technology

 

Optically bar-coded beads are fabricated at low cost by photolithography. The beads can be functionalized with nucleic acids, proteins or other probe molecules, allowing large multiplexed assays to be carried out in homogeneous or heterogeneous media.

 

The digital readout system includes a microfluidic transducer, a bar-code reader and fluorescence detection. The digital beads can also be decoded by image processing.

 

 

(a)		(b)
(c)		(d)
(e)

(a) A mixture of digital beads carboxylated with probes are introduced into a small sample volume for all-in-one assay; (b) A microscopic sectional image of 10-digit bar-code beads on a substrate.  For example, using 10-digit representing 0010110101 on a single microbead allows for 1,024 ( = 2¹⁰) unique identification codes; (c) Digital magnetic beads inside a microplate; (d) Microplate imaging; (e) Microfluidic bead decoding and fluorescence detection.

 

►   Advantages

 

MSI’s improved approach offers substantial advantages over the current state-of-the-art in magnetic bead technology. Because of its simplicity, scalability, and extremely low cost (one bead for one test), this technology may fundamentally change the format of in-vitro diagnostics.

• Its flexibility enables new probes to be added quickly to multiplexed (5 -1,024) assays in a single tube.

• The size of the microbead (2,000 beads= 0.8 µl) is so small that assays can be conducted with as little as one droplet of sample.

• The beads’ paramagnetic properties make the technology well suited for washing, purification, and automation protocols.

• The beads support both high speed and high throughput (< 30 seconds for thousands of beads).

• The beads can be mass produced at low cost.

• Reactions are all-in-one and can be carried out in small volumes saving labor, reagents and consumables.

• The technology is adaptable to automation using a 96-well or 384-well plate format.

►   Applications

 

The graphic that follows illustrates a fluorescence assay for BRCA1 Mutation analysis:

 

►   For More Information

Contact Maxwell Sensors to learn how magnetic digital bead technology can benefit your organization.