Lyophilization Vials Compared — Type I Borosilicate vs Cyclic Olefin for Research

Published 2026-08-04 · Lab Supply Finder Editorial

You're pulling a vial out of a -80°C freezer, and you need it in a 37°C water bath in under ten seconds. If you hear a crack, that's a lost sample and a redo. Vial material stops being a spec-sheet footnote at exactly that moment.

For lyophilization, you're choosing between Type I borosilicate glass and cyclic olefin polymer (COP/COC). Both hold a cake, both seal, but they fail differently and cost differently. The short version: Type I borosilicate is the default for thermal shock; cyclic olefin wins on extractables and shatter-resistance. We tested 20 vials of each material from three suppliers per type—freezing, lyophilizing, and thermal cycling them—to score the options. Here's the rubric.

Thermal Shock: Borosilicate Wins, Decisively

Score: Borosilicate 5/5, Cyclic Olefin 2/5 — All 20 borosilicate vials survived ten cycles from -80°C to 37°C; 8 of 20 COP vials warped at the neck, and 2 cracked at the shoulder.

Type I borosilicate has a coefficient of thermal expansion (CTE) of ~3.3 x 10⁻⁶/°C, giving it a fracture-risk threshold around a 160°C differential. Cyclic olefin's CTE is 60-70 x 10⁻⁶/°C—an order of magnitude higher—so it expands and contracts more per degree. That's fine for slow ramps (1°C/min or less), but it's risky for plunge-style thawing. A warped neck won't seat a stopper, and you'll get vacuum loss during secondary drying.

| Material | CTE (x10⁻⁶/°C) | Thermal shock limit (ΔT) | Shatter risk | Price per unit (2 mL) | |----------|----------------|--------------------------|--------------|-----------------------| | Type I borosilicate | 3.3 | ~160°C | High if dropped | $0.15 - $0.45 | | Cyclic olefin (COP) | 60-70 | ~80-100°C | Very low | $0.60 - $1.20 |

Extractables: COP Is Cleaner, But Glass Is Fine for Most Work

Score: Borosilicate 4/5, Cyclic Olefin 5/5 — Borosilicate leaches 0.5-1.5 ppm boron in 0.1% TFA after 24 hours; COP shows no detectable extractables under USP <661>.

Borosilicate releases trace boron, sodium, and silica, especially at low pH. For a peptide in 0.1% TFA, that's measurable but usually irrelevant. For ICP-MS or trace metal work, it's a signal killer. COP has near-zero extractables, but it's more permeable to oxygen and water vapor (0.1-0.5 cc/m²/day vs. essentially zero for glass)—so a lyophilized cake stored for months in COP risks moisture ingress. Also note: your stopper leaches more than either vial material. We tested identical stoppers across both vial types, and the stopper dominated the extractables profile.

Neck Format: Crimp Beats Screw for Lyophilization

Score: Crimp 5/5, Screw 3/5 — Crimp vials held vacuum in 20/20 runs at 100 mTorr; screw caps failed in 3/20 runs.

Crimp necks use a slotted stopper that sits partially open during primary drying and seats fully when you crimp the aluminum seal. Screw neck closures reduce sublimation area by 20-30%, extending primary drying time by 10-20%. Screw caps can also back off during vacuum, silently breaking the seal—you won't know until the cake collapses. The only reason to choose screw neck: a one-off run of 10 vials where a crimper ($150-300) isn't worth it.

Supplier Scorecard: We Ordered From All Six

We ordered 2 mL vials from DWK Life Sciences (Kimble), Corning, and Wheaton for borosilicate; West Pharmaceutical, SCHOTT, and Afton Scientific for COP. Prices below are per unit at qty 100.

| Supplier | Material | Price/unit | COA transparency | Lead time | Trust | Support | Rubric | |----------|----------|------------|------------------|-----------|-------|---------|--------| | DWK (Kimble) | Borosilicate | $0.18 | Per-lot cert on request, 24h turnaround | 3-5 days | ISO 9001:2015, USP <660> | Email-only | 4/5 | | Corning | Borosilicate | $0.22 | Per-lot COA downloadable, includes USP <381> | 2-4 days | FDA-registered facility | Phone support | 5/5 | | Wheaton | Borosilicate | $0.15 | Generic COA, not per-lot | 5-7 days | ISO 9001:2015 | Ticket-based | 3/5 | | West Pharmaceutical | COP | $0.85 | Per-lot COA with full extractables | 10-14 days | Industry leader in closures | Technical staff | 4/5 | | SCHOTT | COP | $0.95 | Per-lot COA, includes USP <661> | 7-10 days | Top-tier manufacturer | Application engineers | 5/5 | | Afton Scientific | COP | $0.65 | Basic specs only, on request | 14+ days | Smaller player | Minimal | 2/5 |

Corning wins for borosilicate—their per-lot COA includes the USP <381> acid neutralization number, which is what reviewers actually ask for. The $0.04/unit premium over DWK is worth it for a 50-vial month. SCHOTT wins for COP—full USP <661> panel on the COA and a week faster lead time than West. Afton's lower price is a trap; no per-lot documentation means you're gambling on batch consistency.

Before you buy, measure the flange. A 13 mm crimp vial has a flange diameter of 13 mm ± 0.25 mm per ISO 8362-1. We had a batch of Wheaton vials measure 13.4 mm—they fit the tray but jammed in the stoppering mechanism.

Bottom Line by Use Case

For a 50-vial month of standard research lyophilization (peptides, proteins, small molecules): Corning Type I borosilicate with crimp necks. Thermal shock is proven, extractables are manageable, and the per-lot COA keeps you audit-ready. $0.22/unit.

For a one-time 5-vial test: Buy DWK or Wheaton, skip the COA request, and save the $0.04-0.07/unit. $0.15-0.18/unit.

For cyclic olefin (BSL-3 shatter-proof handling, trace analysis, or pre-sterilized single-use): SCHOTT. $0.95/unit.

For a 100-vial month with tight budget: DWK borosilicate at $0.18/unit—just budget for the 24-hour COA wait.

And remember: a good butyl stopper costs more than the vial and is the most likely point of failure. Price the whole closure system, not just the glass.