{"product_id":"caplugs-300-2912-y20-ldpe-test-tube-stopper-12mm-yellow","title":"Test Tube Stoppers, LDPE, Yellow, BD® Compatible — 300-2912-Y20 | 1000\/Bag | Caplugs® Evergreen","description":"\u003ch2\u003eTest Tube Stopper Caps for 12 mm Test Tubes, LDPE, Yellow — 300-2912-Y20 | 1000\/Bag\u003c\/h2\u003e \u003ctable\u003e \u003cthead\u003e\u003ctr\u003e\u003cth colspan=\"2\"\u003eQuick Reference — 300-2912-Y20\u003c\/th\u003e\u003c\/tr\u003e\u003c\/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eTube OD\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e12 mm\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eCap Type\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003eStopper (plug-in friction fit)\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eMaterial\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003eLow-Density Polyethylene (LDPE)\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eColor\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003eYellow\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eColor Convention\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003eYellow stoppers correspond to the SPS (Sodium Polyanethol Sulfona\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eTube Types\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003eStandard 12 × 75 mm, 12 × 100 mm glass and PS culture tubes\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eSterility\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003eNon-Sterile\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003ePack Size\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e1000 \/ Bag\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003ePrice\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e$44.13 \/ Bag ($0.0442 \/ stopper)\u003c\/td\u003e \u003c\/tr\u003e \u003c\/tbody\u003e \u003c\/table\u003e \u003ch2\u003eTechnical Narrative\u003c\/h2\u003e \u003cp\u003eThe Caplugs® Evergreen is a yellow LDPE stopper cap for 12 mm OD test tubes — the most widely used diameter in general laboratory and clinical tube formats. 12 mm covers standard 12 × 75 mm and 12 × 100 mm glass and PS culture tubes, BD Vacutainer-compatible collection tube sizes, and the most common polypropylene clinical test tube formats. Yellow stoppers correspond to the SPS (Sodium Polyanethol Sulfonate) blood culture tube convention in the CLSI H3 system, and are also used for ACD (Acid Citrate Dextrose) tube designation — making yellow the natural stopper color for blood culture tube closure and microbiology specimen batches in color-coded routing systems.\u003c\/p\u003e \u003cp\u003eThe 12 mm size represents the broadest compatibility range in the Caplugs® Evergreen stopper series — it is the format most laboratories require in the largest volumes for clinical chemistry, microbiology culture, and hematology specimen tube workflows. LDPE construction provides the flex modulus required for stopper-style friction retention across repeated insertion\/removal cycles without fracture, while maintaining flexibility at -20°C for frozen archive tube access and retaining seal engagement at 37°C incubation temperature. LDPE chemical inertness to serum, plasma, urine, and broth media ensures no cap leaching into tube contents during storage.\u003c\/p\u003e \u003cp\u003eAt $44.13 per 1000\/Bag — $0.0442 per stopper — the delivers yellow 12 mm stopper coverage at per-stopper economics for high-volume tube capping programs. The complete 12 mm color range is available — see the table below to select the color matching your laboratory's tube routing protocol.\u003c\/p\u003e \u003ch2\u003eTechnical Specifications — Caplugs® Evergreen \u003c\/h2\u003e \u003ctable\u003e \u003cthead\u003e\u003ctr\u003e \u003cth\u003eSpecification\u003c\/th\u003e \u003cth\u003eValue\u003c\/th\u003e \u003c\/tr\u003e\u003c\/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd\u003ePart Number\u003c\/td\u003e \u003ctd\u003e\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eCaplugs Item #\u003c\/td\u003e \u003ctd\u003e3002912Y20E1\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eTube OD\u003c\/td\u003e \u003ctd\u003e12 mm\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eCap Style\u003c\/td\u003e \u003ctd\u003eStopper — plug-in friction fit\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eMaterial\u003c\/td\u003e \u003ctd\u003eLow-Density Polyethylene (LDPE)\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eColor\u003c\/td\u003e \u003ctd\u003eYellow\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eColor Convention\u003c\/td\u003e \u003ctd\u003eYellow stoppers correspond to the SPS (Sodium Polyanethol Sulfonate) blood cultu\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eTube Compat.\u003c\/td\u003e \u003ctd\u003eStandard 12 × 75 mm and 12 × 100 mm glass and PS culture tubes\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eTemp. Range\u003c\/td\u003e \u003ctd\u003e-20°C to +60°C\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eSterility\u003c\/td\u003e \u003ctd\u003eNon-Sterile\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003ePack Size\u003c\/td\u003e \u003ctd\u003e1000 \/ Bag\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eBPA\/Phthalate\u003c\/td\u003e \u003ctd\u003eBPA-free; no phthalate plasticizers\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eCountry of Origin\u003c\/td\u003e \u003ctd\u003eMade in U.S.A. (California)\u003c\/td\u003e \u003c\/tr\u003e \u003c\/tbody\u003e \u003c\/table\u003e \u003ch2\u003eTest Tube Stopper Application Compatibility — \u003c\/h2\u003e \u003cp\u003eThe yellow 12 mm LDPE stopper fits standard 12 mm OD test tubes for the following workflows:\u003c\/p\u003e \u003ctable\u003e \u003cthead\u003e\u003ctr\u003e \u003cth\u003eApplication\u003c\/th\u003e \u003cth\u003eTube \/ Specimen Type\u003c\/th\u003e \u003cth\u003eNotes\u003c\/th\u003e \u003c\/tr\u003e\u003c\/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd\u003eCulture tube capping\u003c\/td\u003e \u003ctd\u003eMicrobiology culture tubes, TSB, BHI, LB broth\u003c\/td\u003e \u003ctd\u003eLDPE stopper seals tube during incubation; flex retained at 37°C\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eSpecimen tube archiving\u003c\/td\u003e \u003ctd\u003eSerum, plasma, urine in refrigerated\/frozen storage\u003c\/td\u003e \u003ctd\u003ePrevents evaporation during extended cold storage\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eClinical tube color routing\u003c\/td\u003e \u003ctd\u003e12 mm OD clinical tubes in color-coded systems\u003c\/td\u003e \u003ctd\u003eCLSI-convention color stoppers for specimen-type routing\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eCell culture capping\u003c\/td\u003e \u003ctd\u003eSuspension culture, virus propagation\u003c\/td\u003e \u003ctd\u003eStopper allows gas exchange while preventing contamination\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003ePneumatic tube transport\u003c\/td\u003e \u003ctd\u003eSample tube transport in clinical tube systems\u003c\/td\u003e \u003ctd\u003eLDPE flex retention survives transport acceleration forces\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eChemistry tube sealing\u003c\/td\u003e \u003ctd\u003ePre-analysis sample tube closure\u003c\/td\u003e \u003ctd\u003eLDPE inert to serum\/plasma; no leaching into specimen\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eHematology specimen capping\u003c\/td\u003e \u003ctd\u003eEDTA blood tubes (lavender), CBC prep tubes\u003c\/td\u003e \u003ctd\u003eLavender stoppers for EDTA-tube closure; white for barcode-labeled CBC\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eResearch tube closure\u003c\/td\u003e \u003ctd\u003eBuffer, reagent, stock solution tube archiving\u003c\/td\u003e \u003ctd\u003eStopper seals reusable glass and PS tubes between uses\u003c\/td\u003e \u003c\/tr\u003e \u003c\/tbody\u003e \u003c\/table\u003e \u003cp\u003e\u003cem\u003eAlways validate stopper fit with your specific tube brand before bulk purchase — 12 mm OD tubes vary in opening diameter by wall thickness. Request a free sample to confirm friction-fit retention.\u003c\/em\u003e\u003c\/p\u003e \u003ch2\u003eChemical Resistance — Low-Density Polyethylene (LDPE)\u003c\/h2\u003e \u003cp\u003eLDPE provides the flexibility essential for stopper-format tube caps and broad chemical inertness to clinical specimen matrices.\u003c\/p\u003e \u003ctable\u003e \u003cthead\u003e\u003ctr\u003e \u003cth\u003eReagent \/ Condition\u003c\/th\u003e \u003cth\u003eCompatibility\u003c\/th\u003e \u003c\/tr\u003e\u003c\/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd\u003eAqueous buffers \/ water\u003c\/td\u003e \u003ctd\u003e✓ Excellent\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eUrine \/ serum \/ plasma\u003c\/td\u003e \u003ctd\u003e✓ Excellent\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eCell culture media\u003c\/td\u003e \u003ctd\u003e✓ Excellent\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eDilute acids (\u0026lt;10%)\u003c\/td\u003e \u003ctd\u003e✓ Good\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eDilute alkalies (pH \u0026lt;12)\u003c\/td\u003e \u003ctd\u003e✓ Good\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eShort-chain alcohols (brief)\u003c\/td\u003e \u003ctd\u003e✓ Good\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eDMSO (≤10%)\u003c\/td\u003e \u003ctd\u003e✓ Good — brief contact\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eConcentrated organic solvents\u003c\/td\u003e \u003ctd\u003e✗ Not recommended\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eAutoclave (121°C)\u003c\/td\u003e \u003ctd\u003e✗ Not compatible\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003eStorage at -20°C\u003c\/td\u003e \u003ctd\u003e✓ Suitable — LDPE retains flexibility\u003c\/td\u003e \u003c\/tr\u003e \u003c\/tbody\u003e \u003c\/table\u003e \u003ch2\u003eComplete 12 mm Stopper Color Range — Caplugs® Evergreen\u003c\/h2\u003e \u003cp\u003eAll 12 mm LDPE stopper colors are identical in material and friction-fit performance. Color selection is protocol-driven:\u003c\/p\u003e \u003ctable\u003e \u003cthead\u003e\u003ctr\u003e \u003cth\u003ePart Number\u003c\/th\u003e \u003cth\u003eColor\u003c\/th\u003e \u003cth\u003ePrice\/1000\u003c\/th\u003e \u003cth\u003ePrimary Convention \/ Use\u003c\/th\u003e \u003c\/tr\u003e\u003c\/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd\u003e300-2912-B20\u003c\/td\u003e \u003ctd\u003eBlue\u003c\/td\u003e \u003ctd\u003e$44.13\u003c\/td\u003e \u003ctd\u003eCitrate anticoagulant \/ blue-top convention\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e300-2912-E20\u003c\/td\u003e \u003ctd\u003eOrange\u003c\/td\u003e \u003ctd\u003e$44.13\u003c\/td\u003e \u003ctd\u003eSTAT \/ priority specimen designation\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e300-2912-G20\u003c\/td\u003e \u003ctd\u003eGreen\u003c\/td\u003e \u003ctd\u003e$44.13\u003c\/td\u003e \u003ctd\u003eGeneral specimen-type or batch routing\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e300-2912-K20\u003c\/td\u003e \u003ctd\u003eFuchsia\u003c\/td\u003e \u003ctd\u003e$44.13\u003c\/td\u003e \u003ctd\u003eGYN \/ gynecologic specimen designation\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e300-2912-L20\u003c\/td\u003e \u003ctd\u003eLavender\u003c\/td\u003e \u003ctd\u003e$44.13\u003c\/td\u003e \u003ctd\u003eEDTA anticoagulant \/ lavender-top convention\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e300-2912-R20\u003c\/td\u003e \u003ctd\u003eRed\u003c\/td\u003e \u003ctd\u003e$44.13\u003c\/td\u003e \u003ctd\u003eSerum \/ red-top convention\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e300-2912-W20\u003c\/td\u003e \u003ctd\u003eWhite\u003c\/td\u003e \u003ctd\u003e$44.13\u003c\/td\u003e \u003ctd\u003eUniversal default \/ label-based ID\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003e\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e\u003cstrong\u003eYellow\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e$44.13\u003c\/td\u003e \u003ctd\u003eSPS culture \/ special tube designation\u003c\/td\u003e \u003c\/tr\u003e \u003c\/tbody\u003e \u003c\/table\u003e \u003ch2\u003eLaboratory Applications\u003c\/h2\u003e \u003cp\u003eThe serves clinical and research microbiology programs capping culture tubes; clinical chemistry and hematology labs using CLSI-convention color-coded stopper routing; anatomic pathology programs designating specimen-type batches with color stoppers; cell culture programs capping tubes during incubation; and any laboratory requiring high-volume friction-fit closure on 12 mm OD test tubes.\u003c\/p\u003e \u003ch2\u003eU.S. Manufacturing, Quality \u0026amp; Institutional Procurement\u003c\/h2\u003e \u003cp\u003eEvery Caplugs® Evergreen lot is precision-molded at our California manufacturing facility and subject to rigorous dimensional inspection and material purity verification. We supply reference laboratories, hospital systems, and federal procurement offices under institutional pricing programs with blanket-order support and same-day shipping. \u003ca href=\"#request-sample\"\u003eRequest a free sample below\u003c\/a\u003e to validate stopper fit with your tube brand before committing to volume.\u003c\/p\u003e \u003ch2\u003eFrequently Asked Questions — Caplugs® Evergreen \u003c\/h2\u003e \u003ch3\u003eWhat is the clinical color convention for yellow 12 mm tube stoppers?\u003c\/h3\u003e \u003cp\u003eYellow stoppers correspond to the SPS (Sodium Polyanethol Sulfonate) blood culture tube convention in the CLSI H3 system, and are also used for ACD (Acid Citrate Dextrose) tube designation — making yellow the natural stopper color for blood culture tube closure and microbiology specimen batches in color-coded routing systems. The Caplugs® Evergreen 12 mm stopper range covers all 8 CLSI H3 tube-top color conventions and general-purpose colors — see the complete color table above for the full range.\u003c\/p\u003e \u003ch3\u003eWhich CLSI H3 tube-top conventions does the 12 mm stopper range cover?\u003c\/h3\u003e \u003cp\u003eThe Caplugs® Evergreen 12 mm stopper range covers the primary CLSI H3 vacuum tube color conventions: Red (300-2912-R20): serum\/no additive; Lavender (300-2912-L20): EDTA anticoagulant (CBC, HbA1c, molecular); Blue (300-2912-B20): sodium citrate anticoagulant (coagulation); Yellow : SPS\/ACD (blood culture, HLA); Green (300-2912-G20): heparin (plasma, stat chemistry); Orange (300-2912-E20): STAT\/thrombin activation; White (300-2912-W20): universal\/barcode-labeled; Fuchsia (300-2912-K20): GYN\/anatomic pathology designation. All eight are available at $44.13\/1000. Select colors based on your laboratory's specific tube routing protocol.\u003c\/p\u003e \u003ch3\u003eWhy is LDPE used for stopper caps rather than PP or PS?\u003c\/h3\u003e \u003cp\u003eStopper-style caps work by friction fit — the plug must compress under insertion and spring back against the tube wall to retain. PP and PS are too rigid and crack under repeated insertion\/removal cycles. LDPE's low-density flex modulus allows thousands of stopper cycles without fracture, retains flexibility at -20°C to prevent brittle failure during frozen archive access, and provides chemical inertness to clinical specimen matrices.\u003c\/p\u003e \u003cscript type=\"application\/ld+json\"\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"Product\",\n  \"name\": \"Test Tube Stopper Caps, For 12 mm Test Tubes, Non-Sterile, Low-Density Polyethylene (LDPE), Yellow \\u2014 300-2912-Y20 | 1000\/Bag | Caplugs\\u00ae Evergreen\",\n  \"description\": \"Caplugs\\u00ae Evergreen 300-2912-Y20. LDPE test tube stopper caps, 12 mm, yellow, 1000\/Bag. Color-coded tube closure. BPA-free. USA.\",\n  \"sku\": \"3002912Y20E1\",\n  \"mpn\": \"300-2912-Y20\",\n  \"material\": \"Low-Density Polyethylene (LDPE)\",\n  \"color\": \"Yellow\",\n  \"brand\": {\n    \"@type\": \"Brand\",\n    \"name\": \"Caplugs\\u00ae Evergreen\"\n  },\n  \"manufacturer\": {\n    \"@type\": \"Organization\",\n    \"name\": \"Caplugs\\u00ae Evergreen\",\n    \"address\": {\n      \"@type\": \"PostalAddress\",\n      \"addressCountry\": \"US\",\n      \"addressRegion\": \"CA\"\n    }\n  },\n  \"offers\": {\n    \"@type\": \"Offer\",\n    \"price\": \"44.13\",\n    \"priceCurrency\": \"USD\",\n    \"availability\": \"https:\/\/schema.org\/InStock\",\n    \"itemCondition\": \"https:\/\/schema.org\/NewCondition\",\n    \"seller\": {\n      \"@type\": \"Organization\",\n      \"name\": \"LabSupplies\"\n    }\n  },\n  \"additionalProperty\": [\n    {\n      \"@type\": \"PropertyValue\",\n      \"name\": \"Tube OD\",\n      \"value\": \"12 mm\"\n    },\n    {\n      \"@type\": \"PropertyValue\",\n      \"name\": \"Cap Style\",\n      \"value\": \"Stopper (plug-in friction fit)\"\n    },\n    {\n      \"@type\": \"PropertyValue\",\n      \"name\": \"Pack Size\",\n      \"value\": \"1000 \/ Bag\"\n    },\n    {\n      \"@type\": \"PropertyValue\",\n      \"name\": \"Sterility\",\n      \"value\": \"Non-Sterile\"\n    },\n    {\n      \"@type\": \"PropertyValue\",\n      \"name\": \"Country of Origin\",\n      \"value\": \"United States\"\n    },\n    {\n      \"@type\": \"PropertyValue\",\n      \"name\": \"BPA Free\",\n      \"value\": \"Yes\"\n    },\n    {\n      \"@type\": \"PropertyValue\",\n      \"name\": \"Color Convention\",\n      \"value\": \"Yellow stoppers correspond to the SPS (Sodium Polyanethol Sulfonate) blood cultu\"\n    }\n  ]\n}\n\u003c\/script\u003e \u003cscript type=\"application\/ld+json\"\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What is the clinical color convention for yellow 12 mm tube stoppers?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yellow stoppers correspond to the SPS (Sodium Polyanethol Sulfonate) blood culture tube convention in the CLSI H3 system, and are also used for ACD (Acid Citrate Dextrose) tube designation \\u2014 making yellow the natural stopper color for blood culture tube closure and microbiology specimen batches in color-coded routing systems. The Caplugs\\u00ae Evergreen 12 mm stopper range covers all 8 CLSI H3 tube-top color conventions and general-purpose colors \\u2014 see the complete color table above for the full range.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Which CLSI H3 tube-top conventions does the 12 mm stopper range cover?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"The Caplugs\\u00ae Evergreen 12 mm stopper range covers the primary CLSI H3 vacuum tube color conventions: Red (300-2912-R20): serum\/no additive; Lavender (300-2912-L20): EDTA anticoagulant (CBC, HbA1c, molecular); Blue (300-2912-B20): sodium citrate anticoagulant (coagulation); Yellow (300-2912-Y20): SPS\/ACD (blood culture, HLA); Green (300-2912-G20): heparin (plasma, stat chemistry); Orange (300-2912-E20): STAT\/thrombin activation; White (300-2912-W20): universal\/barcode-labeled; Fuchsia (300-2912-K20): GYN\/anatomic pathology designation. All eight are available at $44.13\/1000. Select colors based on your laboratory's specific tube routing protocol.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Why is LDPE used for stopper caps rather than PP or PS?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Stopper-style caps work by friction fit \\u2014 the plug must compress under insertion and spring back against the tube wall to retain. PP and PS are too rigid and crack under repeated insertion\/removal cycles. LDPE's low-density flex modulus allows thousands of stopper cycles without fracture, retains flexibility at -20\\u00b0C to prevent brittle failure during frozen archive access, and provides chemical inertness to clinical specimen matrices.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e","brand":"Caplugs® Evergreen","offers":[{"title":"Default Title","offer_id":48567097852136,"sku":"300-2912-Y20","price":44.13,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0694\/5361\/1240\/files\/300-2912-Y20.png?v=1779031865","url":"https:\/\/labsupplies.com\/products\/caplugs-300-2912-y20-ldpe-test-tube-stopper-12mm-yellow","provider":"LabSupplies.com","version":"1.0","type":"link"}