Tissue Embedding Cassettes with Stainless Steel Covers — Polypropylene, Natural, 500/Bag (258-4045-030)
These polypropylene tissue embedding cassettes pair a natural PP body with a stainless steel cover to deliver the mechanical security surgical pathology laboratories need during automated tissue processing. Supplied unassembled — 500 cassette bodies and 500 stainless steel covers per bag — they are compatible with the full histology chemical sequence including 10% NBF formalin fixation, graded ethanol dehydration, xylene clearing, and paraffin infiltration at 56–65°C. The natural PP body accepts pencil, ballpoint pen, and laser engraving directly on the cassette surface, eliminating the label-loss risk associated with adhesive identification during processor agitation cycles.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number (MPN) | 258-4045-030 |
| Cassette Body Material | Polypropylene (PP) |
| Cover Material | Stainless Steel |
| Color | Natural |
| Hole Pattern | Standard histology cassette mesh |
| Assembly State | Unassembled — 500 PP cassette bodies + 500 stainless steel covers per bag |
| Formalin Compatibility | Compatible (10% NBF) |
| Xylene Compatibility | Compatible |
| Paraffin Compatibility | Compatible (56–65°C infiltration) |
| Sterility | Non-Sterile |
| Pack Size | 500/Bag |
| BPA / Phthalates | BPA-free; no phthalate plasticizers |
| Country of Origin | USA (California) |
Applications
- Routine surgical pathology — formalin-fixed tissue specimens including prostate, breast, colon, and skin biopsies
- Large specimen processing — excisional biopsies, lymph nodes, and surgical resections requiring dimensionally stable cassette bodies throughout the processing sequence
- Automated tissue processor runs where plastic cover float-out, warping, or loss in agitation baskets disrupts processing continuity and risks specimen integrity
- Pre-labeling workflows — the unassembled format allows specimens to be identified on the cassette body (pencil, pen, or laser engraving) before assembly and loading
- Paraffin embedding and block-face preparation — consistent PP cassette geometry maintains embedding orientation through infiltration and cooling
Compatibility
These cassettes are designed to work as a cost-effective replacement for Thermo Fisher® histology cassettes and are compatible with industry-standard automated tissue processors including the Thermo Scientific™ Excelsior™, Leica ASP300S, and Sakura Tissue-Tek® platforms. The stainless steel cover provides the mass and rigidity needed to remain positively locked on the PP cassette base at all agitation speeds used in these processors, preventing the cover-detachment events that contaminate processor baths and compromise specimen integrity. Buyers transitioning from OEM or other supplier cassettes should confirm that the standard mesh hole pattern is consistent with their laboratory's embedding mold and processor basket specifications before switching at scale.
Chemical Resistance
| Reagent / Condition | Compatibility |
|---|---|
| 10% Neutral Buffered Formalin (NBF) | Compatible |
| Graded ethanol (dehydration series) | Excellent |
| Xylene / xylene substitutes (clearing) | Compatible |
| Paraffin wax (56–65°C infiltration) | Compatible |
| Aqueous buffers / saline | Excellent |
| Acetone / chlorinated solvents | Not recommended |
Quality & Procurement
Made in USA (California), these Caplugs® Evergreen embedding cassettes are manufactured from BPA-free, phthalate-free polypropylene resin. LabSupplies.com is an authorized dealer of Caplugs® Evergreen laboratory consumables and ships from USA inventory, with volume pricing available for high-throughput surgical pathology programs, hospital systems, and reference laboratories procuring on institutional or grant-funded accounts.
Frequently Asked Questions
Why choose a stainless steel cover instead of a standard plastic cover?
Plastic covers can float free, warp, or disengage from the cassette body during the agitation cycles of automated tissue processors. The stainless steel cover's mass and rigidity keep it positively locked on the PP cassette base throughout the entire processing run, eliminating cover-detachment events that can interrupt processing, contaminate processor baths, and put specimen integrity at risk.
Are these cassettes supplied already assembled?
No — each bag contains 500 PP cassette bodies and 500 stainless steel covers packed unassembled. This allows laboratory staff to label the cassette body by pencil, ballpoint pen, or laser engraving before assembly and loading, which reduces the label-loss risk associated with adhesive identification methods.
Will these cassettes withstand the full histology processing chemical sequence?
Yes. The polypropylene body is compatible with 10% NBF formalin, graded ethanol, xylene and xylene substitutes, and paraffin wax infiltration at 56–65°C without warping, cracking, or dimensional change. Chlorinated solvents and acetone are not recommended for prolonged contact with polypropylene.
Which automated tissue processors are these cassettes compatible with?
These cassettes are compatible with standard histology tissue processors including the Thermo Scientific™ Excelsior™, Leica ASP300S, and Sakura Tissue-Tek® systems. Confirm that the standard mesh hole pattern and cassette dimensions are consistent with your specific processor basket and embedding mold configuration before making a full transition from your current supplier.