The Z216-05-C18 is a 1.8 mL round-bottom cryotube adapter for the Hermle Z216 series 5 mL reaction tube rotor on the Z216-M / Z216-MK high-speed microcentrifuge chassis — sold as a 6-pack. The 5 mL reaction tube rotor accepts 5 mL conical tubes directly, but cryotubes have smaller envelopes and round-bottom skirted cryotubes (1.8 mL external-thread format) require a dedicated adapter to seat correctly and balance properly at high RCF. Sister adapter to the Z216-05-C10 (1.0 mL flat-cap format) — both serve the same rotor but for different cryotube geometries.
Key Specifications
| SKU | Z216-05-C18 |
| Type | Cryotube adapter — 5 mL position → 1.8 mL round-bottom cryotube |
| Pack quantity | 6 adapters per SKU |
| Tube format accepted | 1 × 1.8 mL round-bottom skirted cryotube per adapter |
| Compatible rotor | Z216 5 mL reaction tube rotor (12-position 5 mL fixed-angle on Z216-M / Z216-MK) |
| Compatible chassis | Z216-M, Z216-MK (refrigerated), and -E voltage variants — Z216 family chassis with the 5 mL reaction tube rotor installed |
| Max. operating speed (with adapter + cryotube) | Per the host 5 mL rotor spec — high-speed microcentrifuge RCF range |
| List price | $248 (6-pack) |
Compatibility & When to Order This SKU
Adapter pairing — Z216 5 mL reaction tube rotor only. The Z216-05-C18 is engineered to fit the 5 mL position envelope on the Z216 5 mL rotor. Order this SKU when:
- Adding 1.8 mL round-bottom cryotube workflow to an existing Z216-M / Z216-MK + 5 mL rotor install.
- Cryostorage aliquot prep for workflows that use 1.8 mL round-bottom skirted cryotubes (a common format in cell-line banking and protein-prep aliquoting).
- Replacement adapters if a current set is damaged or worn.
- Mixed-cryotube-format workflows — pair with the Z216-05-C10 (1.0 mL flat-cap adapter) when the lab handles both flat-cap and round cryotube formats on the same chassis.
Cryotube Envelope Geometry
Round-bottom skirted cryotubes (typical 1.8 mL format from Nunc, Corning, Thermo, Greiner, Wuxi) have:
- A round (rather than flat) bottom that requires a matched concave adapter base to seat fully
- An external-thread skirt that protrudes beyond the cryotube barrel diameter — the C18 adapter's mouth accommodates this skirt
- A typical full length around 49–50 mm with cap
The C18 adapter is dimensioned for this envelope. Using a flat-cap adapter (C10) under a round-bottom skirted cryotube would leave the tube unsupported at the bottom and risk imbalance or tube damage at high RCF.
Application Profile
Cell-line cryopreservation banking — cell-line freezing programs that use 1.8 mL round-bottom skirted cryotubes for the standard freeze format; the spin step concentrates cells before resuspension in cryoprotectant.
Master and working cell bank preparation — research-grade cell banking workflows where each cell-line preparation generates batches of 1.8 mL cryotube aliquots for cryostorage.
Biobank patient-sample aliquots — clinical-research biobanks using 1.8 mL skirted cryotubes for patient-sample aliquots prepared for cryostorage and longitudinal analytical reference.
Protein and reagent aliquoting for freeze storage — antibody, enzyme, and reagent aliquot prep into 1.8 mL cryotubes for −80 °C storage.
Cross-format Z216 microcentrifuge consolidation — labs running both 5 mL conical workflows and 1.8 mL round cryotube workflows can use the same chassis + rotor with the C18 adapter swapped in for cryotube runs.
Loading & Balance
Symmetric adapter loading. Pair adapter positions across the rotor by tube mass; all positions in a balanced pair must use matching adapter + tube format.
Cryotube cap confirmation. Skirted cryotube external-thread caps must be fully torqued before spinning — partial cap seating risks sample loss at high RCF and rotor / adapter contamination.
Adapter seat verification. Confirm each C18 adapter is fully seated in its 5 mL position envelope before loading the cryotube.
Ordering & Configuration
Z216-05-C18 ships as 6 adapters. Cryotubes are operator-supplied (commodity biobank cryotube formats from major commercial suppliers).
Confirm at quote: rotor pairing (Z216 5 mL reaction tube rotor in inventory), chassis pairing (Z216-M or Z216-MK), cryotube format (1.8 mL round-bottom skirted confirmed), pack count needed, and lead time.
Warranty: 5-Year Hermle warranty (3 years full + 2 years drivetrain) on the adapters.
Z216 5 mL rotor cryotube adapter family:
- Z216-05-C18 (this product) — 1.8 mL round-bottom cryotube adapter
- Z216-05-C10 — 1.0 mL flat-cap cryotube adapter
Match the adapter to the cryotube format. Workflows using both cryotube formats benefit from stocking both adapter SKUs.
