SOLVO MDQ Kit™ is the first commercially available CE-IVD approved clinical diagnostic kit for the detection of MDR protein function (MDR1, MRP1, and BCRP) by quantitative flow cytometry.

Learn more about how your patients can benefit from MDR protein function determination.


Autoimmune Diseases

Learn more about the application of SOLVO MDQ KitTM in Rheumatoid Arthritis

Hematologic Malignancies

Learn more about the application of SOLVO MDQ KitTM in Hematologic Malignancies

MDQuest Ltd.

Learn more about us by visiting our main website!




How should I choose a suitable antibody for gating the population of interest?

Antibodies used for immunophenotyping should be directed to extracellular epitopes. The SOLVO MDQ KitTM provides functional tests that require living cells. Thus, cells must not be fixed or permeabilized. In addition, some of the antibodies may interfere with the SOLVO MDQ assay; therefore we strongly recommend to test the antibodies for a possible interference.
Compatible fluorescent conjugates are tabulated below:



Detection channel

Compatible Fluorochromes



~515 nm

PerCP, PerCP Cy5.5



~684 nm


Why blood with heparin cannot be used as anticoagulant?

For the collection of whole blood / bone marrow samples and the separation of mononuclear cells, use of K3EDTA blood collection tube and application of Ficoll density gradient separation is recommended. Special cell preparation tubes with sodium citrate can be used as well. Other anticoagulants like heparin may interfere with the activity of MDR proteins.

How long and in what conditions can a blood sample be stored before performing the assay?

Samples should be processed within 6 hours after drawing. Samples stored beyond 6 hours may undergo serious ATP depletion, leading to inaccurate results. Blood should be stored at room temperature before testing (18–25 °C). Do not freeze the sample.

What materials/instruments do I need to perform the assays?

  • Reagents and consumables for specimen collection and preparation
  • Water bath or thermostated dry block for 37°C incubation of reaction tubes
  • Flow cytometer equipped with one or preferably two (488 nm and 635 nm) lasers and appropriate computer hardware and software
  • Reaction tubes and 15 ml Falcon tubes
  • Micropipette(s) capable of dispensing 5 µl, 20–100 µl, and 200–1000 µl and tips.

Can I also test cultivated cells using the SOLVO MDQ KitTM?

Yes. In this case however, the dead cells should be identified among the cultivated cells and excluded from the analysis using an appropriate membrane impermeable fluorescent dye, such as propidium iodide. This fluorescent dye stains cells with lost membrane integrity, and therefore viable cells appear as a negative population when gated according to propidium iodide fluorescence.

What is the Multidrug Resistance Activity Factor (MAF) that is used for the expression of results?

The SOLVO MDQ KitTM includes an internal standardization, thus, the so-called Multidrug Resistance Activity Factor (MAF) values are independent from the PMT settings whenever the acquisition occurs within the linear range of the equipment. Theoretical value of the Multidrug Resistance Activity Factors ranges between 0 and 100.

What are the expected results, how can they be interpreted?

In the case of hematological malignancies, the MAFC values in the tumor cell population are usually found between 0 and 50, but in extreme cases values can be as high as 70. Studies comparing the MAFC values with the clinical response to the chemotherapeutical treatment suggested that the specimen with a MAFC value <20 can be regarded as MDR negative, while MAFC value >25 is indicative of positive MDR (Karaszi et al. Br J Haematol 112(2): 08–14, 2001.).

Reference intervals determined on CD3+ lymphocytes of a reference population of 120 healthy persons (without any medication, mean age=43.2±14.77 years) with 90% confidence according to the CLSI guideline C28-A3:

MAFC < 32,0

MAFMRP < 12,5

MAFMDR < 25,7

MAFBCRP < 20,8

In drug selected cell lines exhibiting extreme high levels of MDR1/or MRP1 expression, the MAFC values might be as high as 95−98.