Table 1.
Currently known aquaporins (AQP) water transport functional assays.
| Assay | System | Readout | Throughput | Characteristics | References |
|---|---|---|---|---|---|
| Stopped-flow water permeability assay | Suspended AQP-proteoliposomes, vesicles or cells (e.g., erythrocytes) | Light scattering or fluorescence changes | Low; about 10 samples per hour | Requires specialized instrumentation i.e., stopped-flow spectrometer | [ 52,53] |
| Transepithelial assay | Cell monolayers cultured on porous support | Dilution of indicator dye | Low; 12 wells per plate | Virtually free from artifacts Laborious to perform | [ 54] |
| Fluorescence-based assay | Cell monolayers cultured on solid support | Cytoplasmic fluorescence changes | Medium; 96-well plates | Potential artifacts related to interaction of compound with reporter fluorescence Easy to perform | [ 55–57] |
| Oocyte swelling assay | Oocytes from Xenopus laevis | Oocyte imaging | Low; about 2–5 samples per day | Prone to artifacts Technically challenging | [ 3] |
| Erythrocyte lysis assay | Erythrocytes | Cell lysis | High; 96-well plates | Only applicable for AQP1 | [ 58,59] |
| Yeast freeze-thaw assay | Yeast cells | Cell viability | High; 96-well plates | Generic Easy to perform | [ 60] |