diagnoSwiss S.A.
Rte de l'Ile-au-Bois 2 - CH-1870 MONTHEY - Switzerland
Phone: +41 (0)24 471 49 00 - Fax: +41 (0)24 471 49 01 - E-mail: info@diagnoswiss.com - Web: www.diagnoswiss.com
WHY GRAVI™ ?
GRAVI™ is a trademark of DiagnoSwiss, which refers to fluidics within the micro-channel being solely capillary-force and gravity-driven. Solutions flow from the inlet to the outlet of the micro-channel by virtue of the pressure difference resulting from the chip being tilted. The major benefit is that neither pumps, tubes, valves, nor high voltage are required, thus contributing to the high robustness of the system.
What is a GRAVI™- Chip ?
GRAVI™- Chip is a consumable chip harboring 8 parallel micro-channels. The polymer device has incorporated microelectrodes for enzymatic readout. With 24-fold regeneration capacity, GRAVI™- Chips are suitable for the generation of 192 data points.
What is a GRAVI™- Cell ?
GRAVI™- Cell is a USB powered instrument with a GRAVI™- Chip holder and a magnet array for the management of bead- based immunoassays and enzymatic readout of results.
What is GRAVI™- Soft ?
GRAVI™- Soft is an easy-to-use software, which controls the GRAVI™- Cell instrument through the USB port. GRAVI™- Soft is used to program multistep tutorial protocols, to process ELISA tests following the given protocol (with its timer and detection features), and to treat the obtained data. Pre-established ELISA protocols, in either one, two or three steps, are provided also to help users establish further assays.
What is GRAVI™ for ?
The GRAVI™ (instrument, software and micro-chip) platforms are intended for running immunoassays and ELISA tests, in particular following magnetic bead-based protocols.
What is the microfluidics benefit ?
With assays performed in GRAVI™- Chip, the sample and reagent volumes are reduced to 5-30 µl. Given the very small dimensions of the micro-channels, time-to-results is trimmed from hours to 10 minutes.
How to establish an assay ?
With capture antibody linked to magnetic beads (preferably to “tosylate-activated” ones), ELISA tests are easily established with standard reagents.
Which micro-beads are best suited ?
It is recommended to use paramagnetic micro-beads of approx. 1 micron diameter or less, in order to optimize homogeneity of the bead solution. Tosylate activated beads can be obtained from www.invitrogen.com: Dynabeads® MyOne™ Tosylactivated, ordering number 655-01.
How is functionality of GRAVI™- Cell, - Chip & - Soft verified ?
A simple test run with streptavidine-coated beads and biotinylated alkaline phosphatase should be performed.
Where can I purchase substrate ?
For affordable substrate, freeze-dried, ready to be dissolved in detection buffer (MAE, pH 9) and sufficient for 10’000 enzymatic reactions, contact sales@diagnoswiss.com. PAPP substrate, Ordering # RS-001-50.
Must I be knowledgeable about electrochemical signals to use GRAVI™ ?
Not really: electrochemistry is simply the mode of detection used to follow the enzymatic reaction, but it is appropriate to basically understand the kinetics of enzyme assays.
Should I share test validation experience I have gathered ?
A wide variety of commercially available or self-established ELISA and immunoassays can be validated on GRAVI™ platforms. Scientists validating applications for their own research are invited to share new and improved results by completing an application note. DiagnoSwiss will gladly post findings and reward the open source developer (info@diagnoswiss.com).
How do I establish ELISA protocols ?
Tutorial protocols for 1, 2, or 3 step ELISA tests are pre-established and serve as basis for the development of novel methods, whenever required. Protocols for given applications are provided in the GRAVI™- Soft, e.g. for human antibody detection with Protein A coated beads (also see the “Applications” section on www.diagnoswiss.com).
Can the GRAVI™- Cell instrument be coupled to a robotic station ?
An automated version is available under the trade name GRAVI™- Lab, which is a GRAVI™- Cell coupled to a Tecan/Cavro MSP 9250 automatic station. The platform is piloted by GRAVI™- Soft and has the capacity to run 4 x 96 assays, fully unattended. (sales@diagnoswiss.com)
