MUHWA 2mL Cryovials — Self-Standing, External Thread, Sterile, 50/Pack
A cryovial has one job: hold your cells or tissue at -196°C without leaking, cracking, or contaminating. When you pull a rack out of the liquid nitrogen dewar and one vial has turned white because LN2 seeped in through a bad seal, everything in that vial is compromised. If you're lucky, it's a backup aliquot. If you're not, it's your only passage-3 stock of a cell line that took six months to establish.
These vials have an external thread — the threads are on the outside of the vial body, and the cap screws down over them. External threads have one big advantage over internal threads (where the cap has a plug that goes inside the vial): nothing that was on the outside of the vial ever enters the sample space. When you unscrew the cap, the sterile interior is exposed for the first time. Internal-thread vials drag the cap plug past the vial rim during opening, which can introduce whatever was sitting on the rim into your sample.
Self-standing design
The vial has a flat bottom with a small skirt — it stands upright on the bench without a rack. When you're aliquoting 50 vials from a single-cell suspension, you can line them up on the bench in a grid and dispense sequentially without transferring to and from racks. The star-shaped base (visible from underneath) provides stability — the vial won't tip if you nudge it with a pipette tip. At -80°C and in LN2 vapor phase, the PP remains dimensionally stable — the vials won't warp and topple in the freezer box.
Temperature range and materials
Polypropylene vial body, polyethylene cap. PP stays ductile down to -196°C — it won't become brittle and crack under thermal shock. The recommended temperature range is -196°C (liquid nitrogen vapor phase) to 121°C (autoclaving). A note on LN2 liquid phase storage: while PP technically survives -196°C, LN2 can seep past the cap seal over time, and when you warm the vial, the trapped LN2 expands explosively — the vial can burst. Use vapor phase storage or heat-sealable cryo bags for liquid phase.
Specifications
| Volume |
2.0mL (working volume ~1.8mL) |
| Thread type |
External |
| Material |
Body: polypropylene; Cap: polyethylene |
| Temperature |
-196°C to +121°C |
| Sterility |
Gamma-irradiated, SAL 10⁻⁶ |
| Base |
Self-standing, star-shaped skirt |
| Writing area |
Frosted cap top and side panel for marking |
| Pack size |
50 vials |
Labeling for long-term storage
Freezer-grade permanent markers write on the frosted cap and the matte side panel. After writing, let the ink dry for 30 seconds before freezing — wet ink smears in the cold. For archival stocks, double-label: write on both the cap and the side. Caps can pop off under thermal shock, and a labeled side panel is your only identifier when you find a separated cap at the bottom of the cane. Better yet, use cryogenic labels or wrap printed labels with clear tape so the ink doesn't flake off at -80°C.
