Accurately Measuring Viscosity with only 10 μL on m-VROC II

m-VROC^® II is now able to measure viscosity with a sample volume as low as 10 μL. The next generation m-VROC^® II with its advanced features, is an ideal viscometer for measuring precious and limited quantity biological fluids. The highlighted features include the following:

• Small quantity of sample for repeated tests; thanks to the microfluidics & the sample retrieval feature!
• Excellent accuracy, ±2%, and repeatability, ±0.5%

The plot here displays the viscosity results obtained for 150 mg/mL Bovine g-Globulin (BgG), representing a low viscosity sample, and 0.1 wt% high molecular weight Hyaluronic acid (HA), representing a high viscosity sample, at a fixed shear rate and temperature 25 ˚C.

The test was conducted as follows:

1. 10 µL of sample was back-loaded into the 100 µL test syringe using a positive displacement pipette.
2. The m-VROC II unit was equipped with a B05 chip to perform measurements on the sample with five repeats at a fixed shear rate, retrieving the sample when required.
3. Chip Cleaning Station (CCS) performed automatic cleaning of the chip and reservoir at the end of the test with the preset buffer cleaning protocol.

We obtained a set of five viscosity measurements with just 10 µL of each sample, demonstrating the superior repeatability. The average viscosity was measured as 5.38 cP for 150 mg/mL BgG and 200.2 cP for 0.1 wt% HA. The low sample volume capability allows for fast and accurate screening of drug candidates in the early-stage drug development.