MUHWA 3-Way Luer Stopcock — Sterile, 5/Pack
A three-way Luer stopcock gives you fluid control at a junction point: one inlet, two possible outlets, switched by rotating the valve handle. In the lab, it shows up in gravity-fed chromatography columns, vacuum filtration setups, manual perfusion systems, and anywhere you need to divert flow without disconnecting tubing.
The three ports are standard Luer fittings — two female Luer locks and one male Luer slip, or variations depending on the configuration. Luer fittings are the universal small-bore connector in biomedical fluidics: syringes, catheters, IV lines, filtration units, and chromatography tubing adapters all use Luer tapers. The stopcock body is polycarbonate (rigid, clear), and the rotating valve core is polyethylene (self-lubricating, won't seize). The handle rotates 90 degrees between positions with a positive detent — you feel it click into each position, so you know the flow path is aligned.
Flow configurations
With three ports and a rotating valve, you get three flow paths. Position 1: ports A and B are connected, port C is closed. Position 2: ports A and C are connected, port B is closed. Position 3: all three ports connected (on some models — check the valve design). In practice, the most common use case is Position 1 for normal flow, Position 2 for diverting to waste or to a sample collection vessel. The valve can also be set partway between positions for partial flow to two outlets — useful for splitting a perfusion stream.
Specifications
| Ports | 3 Luer ports (configuration varies by model) |
| Body material | Polycarbonate, clear |
| Valve core | Polyethylene |
| Handle positions | 3-way, 90-degree rotation, detented |
| Sterility | EtO-sterilized, individually wrapped |
| Pack size | 5 stopcocks |
Using Luer stopcocks in the lab
For gravity column chromatography: attach the column outlet to the female port, the collection tube to one male port, and a waste line to the other male port. During column equilibration, divert flow to waste. When the sample is loaded and the elution begins, switch to the collection port and start collecting fractions. For vacuum filtration: connect the vacuum line to one port, the filtration flask to another, and use the third as a vent to release vacuum without disconnecting tubing. Always confirm the flow path before starting — rotate the handle fully to the detent position and give the tubing a gentle tug at each connection to verify it's secure.
