{"product_id":"caplugs-300-3532-z20-20-ml-vials-30-ml-centrifuge-tubes-screw","title":"20 mL Centrifuge Tubes, HDPE, Black — 300-3532-Z20 | 1000\/Bag | Caplugs® Evergreen","description":"\u003ch2\u003eScrew Caps for 20 mL Vials \/ 30 mL Centrifuge Tubes — HDPE, Black, 1000\/Bag (300-3532-Z20)\u003c\/h2\u003e\n\u003cp\u003eThese replacement screw caps are molded from high-density polyethylene (HDPE) and sized to fit 20 mL vials and 30 mL centrifuge tubes, providing a secure, re-sealable closure for sample storage and processing. Supplied non-sterile in bulk (1000\/Bag), the black color offers light-blocking utility for light-sensitive samples and convenient visual differentiation in multi-tube workflows. Part number 300-3532-Z20 is an economical stocking choice for labs that routinely cap large numbers of tubes.\u003c\/p\u003e\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003ePart Number (MPN)\u003c\/td\u003e\n\u003ctd\u003e300-3532-Z20\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFits\u003c\/td\u003e\n\u003ctd\u003e20 mL Vials \/ 30 mL Centrifuge Tubes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eClosure Type\u003c\/td\u003e\n\u003ctd\u003eScrew Cap\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaterial\u003c\/td\u003e\n\u003ctd\u003eHigh-Density Polyethylene (HDPE)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eColor\u003c\/td\u003e\n\u003ctd\u003eBlack\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSterility\u003c\/td\u003e\n\u003ctd\u003eNon-Sterile\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePack Size\u003c\/td\u003e\n\u003ctd\u003e1000\/Bag\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCountry of Origin\u003c\/td\u003e\n\u003ctd\u003eUSA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch2\u003eApplications\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eRe-sealing 20 mL vials and 30 mL centrifuge tubes for sample storage\u003c\/li\u003e\n\u003cli\u003eCapping tubes containing light-sensitive reagents, specimens, or extracts where black closures help reduce photodegradation\u003c\/li\u003e\n\u003cli\u003eColor-coded tube identification in multi-sample or multi-study workflows\u003c\/li\u003e\n\u003cli\u003eBulk re-capping applications in high-throughput clinical, environmental, or research laboratories\u003c\/li\u003e\n\u003cli\u003eReplacing damaged or missing caps on compatible vials and centrifuge tubes\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eMaterial \u0026amp; Chemical Resistance\u003c\/h2\u003e\n\u003cp\u003eHigh-density polyethylene offers broad general chemical resistance, including good compatibility with aqueous solutions, dilute acids and bases, and many common laboratory reagents. HDPE is a rigid, low-moisture-absorbing material well suited to liquid containment; however, it is not recommended for autoclaving and may be affected by prolonged exposure to strong oxidizing acids or halogenated solvents. These general properties make HDPE a reliable choice for diverse sample types in everyday lab use.\u003c\/p\u003e\n\u003ch2\u003eQuality \u0026amp; Procurement\u003c\/h2\u003e\n\u003cp\u003eMade in USA, Caplugs® Evergreen screw caps are produced under ISO 9001 quality management from BPA-free, phthalate-free, latex-free HDPE resin. LabSupplies.com is an authorized dealer and ships from USA inventory, typically same business day for stocking items, with tiered pricing available for institutional and grant-funded laboratories.\u003c\/p\u003e\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eAre these screw caps sterile?\u003c\/strong\u003e\u003cbr\u003eNo — they are supplied non-sterile in 1000\/Bag bulk packaging, which is appropriate for general laboratory storage and non-sterility-critical applications.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill the black color help protect light-sensitive samples?\u003c\/strong\u003e\u003cbr\u003eThe black HDPE construction blocks visible light at the cap, which can help reduce photodegradation of light-sensitive contents when used with an appropriately opaque tube. For complete light protection, the tube itself should also be opaque or amber.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan these caps be autoclaved for sterilization before use?\u003c\/strong\u003e\u003cbr\u003eHDPE is generally not recommended for autoclaving, as the high temperatures and steam pressure involved can deform or compromise the material. For sterile closure applications, consider using pre-sterilized caps or an alternative sterilization method compatible with polyethylene.\u003c\/p\u003e\n\u003cscript type=\"application\/ld+json\"\u003e{\"@context\":\"https:\/\/schema.org\/\",\"@type\":\"Product\",\"name\":\"Screw Caps for 20 mL Vials \/ 30 mL Centrifuge Tubes, HDPE, Black, 1000\/Bag\",\"sku\":\"3003532Z20E1\",\"mpn\":\"300-3532-Z20\",\"brand\":{\"@type\":\"Brand\",\"name\":\"Caplugs® Evergreen\"},\"material\":\"High-Density Polyethylene (HDPE)\",\"color\":\"Black\",\"offers\":{\"@type\":\"Offer\",\"priceCurrency\":\"USD\",\"price\":\"91.42\",\"availability\":\"https:\/\/schema.org\/InStock\"}}\u003c\/script\u003e\n\u003cscript type=\"application\/ld+json\"\u003e{\"@context\":\"https:\/\/schema.org\/\",\"@type\":\"FAQPage\",\"mainEntity\":[{\"@type\":\"Question\",\"name\":\"Are these screw caps sterile?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"No — they are supplied non-sterile in 1000\/Bag bulk packaging, which is appropriate for general laboratory storage and non-sterility-critical applications.\"}},{\"@type\":\"Question\",\"name\":\"Will the black color help protect light-sensitive samples?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"The black HDPE construction blocks visible light at the cap, which can help reduce photodegradation of light-sensitive contents when used with an appropriately opaque tube. For complete light protection, the tube itself should also be opaque or amber.\"}},{\"@type\":\"Question\",\"name\":\"Can these caps be autoclaved for sterilization before use?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"HDPE is generally not recommended for autoclaving, as the high temperatures and steam pressure involved can deform or compromise the material. For sterile closure applications, consider using pre-sterilized caps or an alternative sterilization method compatible with polyethylene.\"}}]}\u003c\/script\u003e","brand":"Caplugs® Evergreen","offers":[{"title":"Default Title","offer_id":48580045504744,"sku":"3003532Z20E1","price":109.7,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0694\/5361\/1240\/files\/300-3532-Z20_02.jpg?v=1779410288","url":"https:\/\/labsupplies.com\/products\/caplugs-300-3532-z20-20-ml-vials-30-ml-centrifuge-tubes-screw","provider":"LabSupplies.com","version":"1.0","type":"link"}