Spotted reagents on a chip - reagent storage

Reagent integration

Lab-on-a-chip devices often require reagent integration. Preloading a device with the needed reagent offers ease of use and reduces handling steps and user-related errors because the amount and constitution of the reagent are already determined. Reagent integration is of special importance in Point-of-Care products, which have to be autonomously used outside of lab environments.


On-chip storage in dried or liquid form

Reagents often are stored on-chip in a dried format. This dried substance will be reconstituted during the assay. One of the benefits of functionalizing chips with reagents in a dried form is that this prolongs the shelf life of the product. The most used method of dispensing reagents onto substrates is through spotting arrays of reagents, which are then dried.

Reagents can also be stored in a liquid form. In these cases, liquids are mostly contained in an integrated blister.

Automated reagents spotting

At Micronit, we offer the ability to deposit picolitre spots with high accuracy on your desired substrate using an in-house automated piezo actuated non-contact dispensing system. This technology is ideal for depositing reagents or spotting microarrays on basically any substrate type. Varying droplet volumes and array types enable the most economical use of your sample and reagent amounts. Furthermore, precise control of humidity and temperature allows for controlled drying of reagents for consistent functional results.

Droplets can be spotted individually, on top of each other, in an array, or even overlapping.

Customized quality control includes:

  • Target recognition and quality control of the spotted samples.
  • Stroboscope camera for visual droplet shape and volume control.

Our experts have experience in spotting various reagents, including proteins (i.e. enzymes, antibodies), nucleic acids (i.e. oligonucleotides), buffers, nanoparticles (i.e. beads), sugars, and surfactants, which supports the integration of all kinds of assays into a microfluidic format.

Spotting specifications for non-contact low volume liquid dispensing:

  • Spotting area up to 80x36cm in size
  • Standard droplets of 360-440pl
  • Additional droplet range extension to 100-800pl
  • Spot dimensions are dependent on reagent and spotting substrate combination
  • Typically: 400pl – Ø 125/150µm | 10nl – Ø ~350µm
  • Spotting accuracy < 5µm
  • Time to spot 1µl < 30s
  • A cooling unit for reagents and target area
  • Controllable humidity

Integrated liquid reagent storage

Lab-on-a-chip devices often require one or more liquid reagents or buffers stored on-chip. The storage of liquid reagents directly on-chip eliminates the need for loading the reagents by manual pipetting in the lab. Loading the blisters with the exact amount of reagent needed prevents unnecessary waste of reagents. We work with thin seal blisters which can be integrated on-chip and allow the releasing of the reagent directly inside the microfluidic structures of the chip. Blisters release accurate volumes of reagent or buffer under the simple pressure of a finger or force applied by a mechanical system. For Point-of-Care products, this allows for the device to be used directly at the patient site.

If you are interested in our capabilities concerning reagent integration for your product, we will gladly advise you.

On-chip functionalities

For other essential on-chip functionalities, see our pages about