Extracellular Vesicle (EV) Isolation from Human Urine Samples Using the EVtrap Approach

To begin, collect the urine samples from healthy individuals. Centrifuge 12 milliliters of sample in a 15 milliliter conical tube to eliminate cell debris in large apoptotic bodies. Then, transfer 10 milliliters of the supernatant into a fresh 15 milliliter tube.

Add one milliliter of loading buffer and 200 microliters of EV trap bead slurry to the sample. Incubate the sample at room temperature for 30 minutes with end over end rotation. To pellet the sample, place the 15 milliliter conical tube on a magnetic separator rack.

Carefully remove the supernatant and re-suspend the beads in one milliliter of washing buffer. Then, transfer the suspension to a 1.5 milliliter micro centrifuge tube and gently pipette to re-suspend the extracellular vesicle or EV-bound beads. Place the micro centrifuge tube on a magnetic separator rack for 1.5 milliliter tubes.

Using a P200 pipette, carefully aspirate the supernatant. Now, wash the beads with one milliliter of washing buffer, followed by two washes with one milliliter of PBS at room temperature. Incubate the beads with 100 microliters of freshly prepared 100 millimolar Triethanolamine for five minutes.

Using 1.5 milliliter micro centrifuge tube magnetic separator rack, collect the eluded solution containing EVs. After combining the eluded solutions, dry the eluit, using a vacuum centrifuge concentrator at four degrees Celsius.