Perfusion System for Cell Culture and Analysis

A perfusion system keeps fresh medium flowing over cultured cells, so nutrient supply and waste removal continue the way they would in living tissue. In a pressure-driven setup like the Elveflow OB1, clean gas pressurizes a sealed reservoir and pushes the medium through your culture vessel. No moving part touches the liquid, so the flow is stable and pulseless from the first second. Set a pressure and medium flows; add a flow sensor and the OB1 holds an exact flow rate for you.

Three reasons a biologist notices. The flow is pulseless, up to 20× steadier than a syringe or peristaltic pump, so shear-sensitive cells stay attached and live imaging stays free of vibration. It reaches steady flow in milliseconds, where a syringe pump can take minutes in a soft setup. And it feeds from a large reservoir, so a run goes for days without a refill. The Elveflow OB1 also drives up to four lines at once and never touches the medium, which keeps sterility simple.

Yes. The Elveflow OB1 has no moving part in contact with the liquid, so it delivers a smooth, continuous flow with none of the pulsing you get from a peristaltic or syringe pump. Pulsation matters because your cells feel it. A fluctuating flow means a fluctuating wall shear stress, which can reduce viability, detach a monolayer, or shift phenotype. And in live imaging it shows up as drift and vibration. Steady flow takes that variable off the table, so what changes in your dish is the biology, not the pump.

Yes, and this is one of the OB1’s strengths for cell analysis. The pump sits off the fluid path and delivers a pulseless flow, so there is no vibration in the field and the culture stays under continuous medium renewal while you image. The Elveflow Smart Interface sends a TTL trigger to start acquisition the moment the flow changes, or takes a trigger from your microscope to start an injection, so your images and your medium changes stay on one clock.

Yes. Place an inline assay downstream of the culture and the OB1’s steady flow lets you follow what the cells consume or secrete as it happens, with no discrete sampling. In one published setup, a perfused liver-cell culture on an Elveflow OB1 was tracked for glucose consumption in near real time [Analytical Chemistry, 2019, 1]. Because the flow held steady, the glucose consumption could be quantified across the whole run.

You set it through the flow rate. Wall shear stress comes from the flow rate and your channel geometry, so you calculate the flow that gives your target shear, then hold that flow. With Elveflow’s pressure-driven control, you enter a target flow rate, an MFS or BFS sensor reads the real flow, and the OB1 trims its pressure until the two match, from 0.1 µL/min to 500 mL/min. Because the loop reacts in milliseconds and stays steady, the shear your cells see holds constant across the run, so it is the variable you test rather than a source of noise.

It can, and the limit is your reservoir, not the pump. The OB1 feeds from reservoirs holding a milliliter to several liters, so the medium lasts and the flow never breaks for a refill. A perfused liver-cell culture on an Elveflow OB1 remained viable for up to ten days in one study [Analytical Chemistry, 2019, 1], and longer runs are a matter of reservoir size and protocol. Over runs like these, automation keeps the result clean: you program the flow and any solution changes once, and the same steps land at the same times no matter who started the run.

Two safeguards cover it. You can cap the volume to inject, so the OB1 delivers a set amount and then stops, which suits a run you have budgeted to the milliliter. Or add an inline bubble detector, which senses a change in the fluid, such as air reaching the line when a reservoir empties, and has the software stop the run on that signal. Either way an overnight or multi-day experiment protects itself, so an empty reservoir ends the run cleanly instead of pushing air through your cells.

Open chambers and multiwell plates lose medium to evaporation, most of all at the edges, the well-known edge effect. As the volume falls, osmolarity and pH shift, nutrients deplete faster, and the oxygen tension changes, and any of these can reduce cell viability and skew your results. To hold the level steady, run the Elveflow OB1 in push–pull: one line pushes fresh medium in at a set flow rate while a second pulls spent medium out at the same rate. The volume in the chamber stays constant, so the culture gets continuous medium renewal while osmolarity, pH and nutrient levels hold steady.

The OB1 is a non-contact pump, so the instrument never touches your medium. The fluid path is only your reservoirs, tubing, and culture vessel, which means fewer parts to sterilize and one less route for contamination. Use autoclavable reservoir adapters and sterile tubing, and prepare the wetted parts as you would for any sterile culture. No sterility certification is claimed for the instrument itself, since it stays outside the sterile path.

Two things do most of the work. Feeding from a sealed reservoir avoids the air a syringe swap pushes in, and an inline bubble trap catches any bubble that forms before it reaches the cells. Worth designing out early: one bubble through a culture can strip a monolayer or ruin an imaging session in seconds. Elveflow’s bubble remover sits in the line for exactly this.

Yes. Run the perfusion as a recirculation loop and the medium returns to its reservoir, so you reuse costly or conditioned medium over long runs. There are a few ways to build the loop; our medium-recirculation workflow walks through the options.

The OB1 runs one to four independent channels. You can perfuse up to four different conditions at once, each with its own medium and flow rate, from a single interface, which makes it a screening tool: compare conditions side by side in one run instead of one after another. And because the flow is pressure-driven, a single channel can feed many identical cultures in parallel, so you run dozens of replicates of the same condition in one setup. Each channel is set on its own, so the conditions stay independent.

With an MFS or BFS flow sensor, the OB1 covers roughly 0.1 µL/min to 500 mL/min, feeding from about a milliliter to ten liters of medium, and more with larger reservoirs. The pump drives any aqueous or biological solution, so standard culture media, buffers, and reagents all work. Which cells you run is a question for your culture vessel and protocol, not the controller.

Almost certainly. The OB1 connects to standard tubing and fittings and drives flow into a culture chamber, a microfluidic slide, or a perfused dish. Published work with it spans liver, endothelial, and neuronal cell models, among others. If your setup is unusual, tell us the vessel and your target flow rate and we will confirm the configuration.