{"product_id":"caplugs-300-3532-dg20-hdpe-screw-cap-20ml-vial-30ml-centrifuge-tube-dark-green","title":"20 mL Centrifuge Tubes, Screw Caps, HDPE, Dark Green — 300-3532-DG20 | 1000\/Bag | Caplugs® Evergreen","description":"\u003ch2\u003e20 mL Vial \u0026amp; 30 mL Centrifuge Tube Screw Caps — HDPE, Dark Green, 1000\/Bag (300-3532-DG20)\u003c\/h2\u003e\n\u003cp\u003eThese dark green High-Density Polyethylene screw caps are designed to close Caplugs® Evergreen 20 mL screw-neck vials and 30 mL centrifuge tubes, providing an IATA P650 compliant leak-free seal for biological specimen transport. The 300-3532-DG20 uses a larger thread specification than the 15 mL cap family (300-3010 \/ 300-3022), sized specifically for the wider neck of 20 mL and 30 mL tube formats. Supplied non-sterile at 1000 caps per bag, these caps support cold-chain storage down to -80°C and are autoclave compatible at 121°C.\u003c\/p\u003e\n\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-DG20\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCap Type\u003c\/td\u003e\n\u003ctd\u003eScrew cap — threaded engagement\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\u003eDark Green\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Compatibility\u003c\/td\u003e\n\u003ctd\u003eCaplugs® Evergreen 20 mL screw-neck vials; 30 mL centrifuge tubes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eThread Note\u003c\/td\u003e\n\u003ctd\u003eLarger thread specification than 300-3010 \/ 300-3022 (15 mL cap family)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIATA P650 Compliance\u003c\/td\u003e\n\u003ctd\u003eYes — leak-free primary container seal\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCryogenic Storage\u003c\/td\u003e\n\u003ctd\u003eCompatible to -20°C and -80°C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAutoclave Compatibility\u003c\/td\u003e\n\u003ctd\u003e121°C \/ 15 psi\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\u003eBPA \/ Phthalates\u003c\/td\u003e\n\u003ctd\u003eBPA-free; no phthalate plasticizers\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 (California)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eApplications\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eCapping 20 mL screw-neck vials for large-volume specimen collection and storage\u003c\/li\u003e\n\u003cli\u003eSealing 30 mL centrifuge tubes during serum and plasma separation workflows\u003c\/li\u003e\n\u003cli\u003eLeak-free closure for courier and air transport of serum, plasma, and urine in large-format tubes (IATA P650)\u003c\/li\u003e\n\u003cli\u003eUltra-low temperature biorepository archiving of 20 mL and 30 mL format tubes at -20°C and -80°C\u003c\/li\u003e\n\u003cli\u003ePre-sterilized cap supply for cell culture and pathogen programs requiring autoclave-compatible closures\u003c\/li\u003e\n\u003cli\u003eColor-coded batch routing and specimen-type differentiation — the distinct dark green color visually separates these tubes from lighter green variants without requiring secondary labels\u003c\/li\u003e\n\u003cli\u003eEnvironmental and field sample collection workflows where a visually unique cap color identifies sample set or processing batch\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eCompatibility\u003c\/h2\u003e\n\u003cp\u003eThese caps are sized for the wider neck of Caplugs® Evergreen 20 mL screw-neck vials and 30 mL centrifuge tubes. The thread specification is intentionally larger than that of the 300-3010 plain cap and 300-3022 sprocket cap used on 15 mL tubes, so the two families are not interchangeable. Before placing a bulk order, validate thread fit against your specific tube format — particularly if your lab uses multiple tube sizes from the 300-series range.\u003c\/p\u003e\n\n\u003ch2\u003eChemical Resistance\u003c\/h2\u003e\n\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eReagent \/ Condition\u003c\/th\u003e\n\u003cth\u003eCompatibility\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eAqueous buffers \/ saline\u003c\/td\u003e\n\u003ctd\u003eExcellent\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDilute acids and bases\u003c\/td\u003e\n\u003ctd\u003eExcellent\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShort-chain alcohols (ethanol, isopropanol)\u003c\/td\u003e\n\u003ctd\u003eGood — suitable for working concentrations\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDMSO (working concentrations)\u003c\/td\u003e\n\u003ctd\u003eGood — suitable for working concentrations\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eChlorinated solvents (chloroform, DCM)\u003c\/td\u003e\n\u003ctd\u003eNot recommended\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAromatic solvents (toluene, xylene)\u003c\/td\u003e\n\u003ctd\u003eNot recommended\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCryogenic storage (to -80°C)\u003c\/td\u003e\n\u003ctd\u003eCompatible — no thread deformation\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAutoclave (121°C \/ 15 psi)\u003c\/td\u003e\n\u003ctd\u003eCompatible\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eQuality \u0026amp; Procurement\u003c\/h2\u003e\n\u003cp\u003eMade in USA at Caplugs® Evergreen's California facility, these caps are manufactured from BPA-free, phthalate-free HDPE resin. The IATA P650 compliant thread design has been validated for leak-free transport of biological specimens in primary containers. LabSupplies.com is an authorized Caplugs® Evergreen dealer and ships from USA inventory, typically same business day for stocking items, with volume pricing available for hospitals, biorepositories, and clinical reference laboratories procuring at scale.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eWill these caps fit my existing 15 mL centrifuge tubes?\u003c\/strong\u003e\u003cbr\u003eNo — the 300-3532-DG20 uses a larger thread specification designed for 20 mL vials and 30 mL centrifuge tubes. The 15 mL tube family uses the 300-3010 or 300-3022 caps, which have a smaller thread diameter. Mixing cap families will result in a poor or non-existent seal.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAre these caps safe for ultra-low temperature freezer storage?\u003c\/strong\u003e\u003cbr\u003eYes. The HDPE material retains dimensional stability and thread engagement through repeated freeze-thaw cycling at both -20°C and -80°C, making these caps suitable for long-term biorepository archiving programs.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eCan I autoclave these caps before use in sterile cell culture or pathogen work?\u003c\/strong\u003e\u003cbr\u003eYes — the caps are autoclave compatible at 121°C \/ 15 psi. They are supplied non-sterile, so autoclaving prior to use is the recommended approach when a sterile closure is required.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhy choose dark green rather than standard green caps?\u003c\/strong\u003e\u003cbr\u003eDark green provides a visually distinct color from lighter green variants within a color-coding system, allowing labs to designate specific tube types, processing batches, or environmental sample sets by cap color alone — reducing reliance on secondary labels and minimizing sorting errors in high-throughput workflows.\u003c\/p\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e{\"@context\":\"https:\/\/schema.org\/\",\"@type\":\"Product\",\"name\":\"20 mL Vial \u0026 30 mL Centrifuge Tube Screw Caps — HDPE, Dark Green, 1000\/Bag\",\"sku\":\"300-3532-DG20\",\"mpn\":\"300-3532-DG20\",\"brand\":{\"@type\":\"Brand\",\"name\":\"Caplugs® Evergreen\"},\"material\":\"High-Density Polyethylene (HDPE)\",\"color\":\"Dark Green\",\"offers\":{\"@type\":\"Offer\",\"priceCurrency\":\"USD\",\"price\":\"114.28\",\"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\":\"Will these caps fit my existing 15 mL centrifuge tubes?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"No — the 300-3532-DG20 uses a larger thread specification designed for 20 mL vials and 30 mL centrifuge tubes. The 15 mL tube family uses the 300-3010 or 300-3022 caps, which have a smaller thread diameter. Mixing cap families will result in a poor or non-existent seal.\"}},{\"@type\":\"Question\",\"name\":\"Are these caps safe for ultra-low temperature freezer storage?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Yes. The HDPE material retains dimensional stability and thread engagement through repeated freeze-thaw cycling at both -20°C and -80°C, making these caps suitable for long-term biorepository archiving programs.\"}},{\"@type\":\"Question\",\"name\":\"Can I autoclave these caps before use in sterile cell culture or pathogen work?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Yes — the caps are autoclave compatible at 121°C \/ 15 psi. They are supplied non-sterile, so autoclaving prior to use is the recommended approach when a sterile closure is required.\"}},{\"@type\":\"Question\",\"name\":\"Why choose dark green rather than standard green caps?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Dark green provides a visually distinct color from lighter green variants within a color-coding system, allowing labs to designate specific tube types, processing batches, or environmental sample sets by cap color alone — reducing reliance on secondary labels and minimizing sorting errors in high-throughput workflows.\"}}]}\u003c\/script\u003e","brand":"Caplugs® Evergreen","offers":[{"title":"Default Title","offer_id":48567884021992,"sku":"300-3532-DG20","price":114.28,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0694\/5361\/1240\/files\/Dark_20Green_2030_20mL_20Cap.png?v=1779073271","url":"https:\/\/labsupplies.com\/products\/caplugs-300-3532-dg20-hdpe-screw-cap-20ml-vial-30ml-centrifuge-tube-dark-green","provider":"LabSupplies.com","version":"1.0","type":"link"}