Skip to product information
1 of 1

Caplugs® Evergreen

Test Tube Stoppers, LDPE, Yellow, BD® Compatible — 300-2913-Y20 | 1000/Bag | Caplugs® Evergreen

Test Tube Stoppers, LDPE, Yellow, BD® Compatible — 300-2913-Y20 | 1000/Bag | Caplugs® Evergreen

Regular price $44.95
Regular price Sale price $44.95
Sale Sold out
Shipping calculated at checkout.

Test Tube Stopper Caps for 13 mm Test Tubes, LDPE, Yellow — 300-2913-Y20 | 1000/Bag

Quick Reference — 300-2913-Y20
Tube OD 13 mm
Cap Type Stopper (plug-in friction fit)
Material Low-Density Polyethylene (LDPE)
Color Yellow
Tube Types 13 × 75 mm and 13 × 100 mm glass and PS culture tubes
Temp Range -20°C to +60°C (LDPE flex range)
Sterility Non-Sterile
Pack Size 1000 / Bag
Price $44.95 / Bag ($0.0450 / stopper)

Technical Narrative

The Caplugs® Evergreen is a yellow LDPE stopper cap for 13 mm OD test tubes — designed for 13 mm OD test tubes used in clinical hematology, coagulation, and microbiology workflows. The 13 mm stopper serves hematology, coagulation, and microbiology culture tube workflows. Yellow stoppers correspond to the SPS/ACD blood culture tube convention and are used to designate blood culture and specialized culture tube batches in color-coded routing systems for 13 mm tube formats.

LDPE's low-density flex modulus provides the compression and spring-back required for friction-fit stopper retention across repeated insertion/removal cycles — the property that makes LDPE the only appropriate material for stopper-style tube caps. LDPE retains flexibility from -20°C through 60°C, preventing brittle failure during frozen archive stopper removal and maintaining seal engagement during incubation. Chemical inertness to serum, plasma, broth media, and aqueous buffers ensures no leaching into tube contents.

At $44.95 per 1000/Bag — $0.0450 per stopper. Also available: 300-2912-Y20 (Yellow 12 mm, $44.13); 300-2916-R20 (Red 16 mm, $66.96).

Technical Specifications — Caplugs® Evergreen

Specification Value
Part Number
Caplugs Item # 3002913Y20E1
Tube OD 13 mm
Cap Style Stopper — plug-in friction fit
Material Low-Density Polyethylene (LDPE)
Color Yellow
Tube Compat. 13 × 75 mm and 13 × 100 mm glass and PS culture tubes
Temp Range -20°C to +60°C
Sterility Non-Sterile
Pack Size 1000 / Bag
BPA/Phthalate BPA-free; no phthalate plasticizers
Country of Origin Made in U.S.A. (California)

Test Tube Stopper Application Compatibility — 13 mm

The 13 mm yellow stopper fits standard 13 mm OD tubes for these workflows:

Application Specimen / Use Notes
Culture tube capping Microbiology culture tubes, TSB, BHI, LB broth LDPE stopper seals tube during incubation; flex retained at 37°C
Specimen tube archiving Serum, plasma, blood in refrigerated/frozen storage Prevents evaporation during extended cold storage
Clinical tube color routing CLSI-convention color stoppers for specimen-type ID Color stop mirrors vacuum tube top-color conventions
Cell culture tube capping Suspension culture, virus propagation Stopper allows gas exchange while preventing contamination
Pneumatic tube transport Sample tube transport in clinical systems LDPE flex retention survives transport acceleration forces
Chemistry tube sealing Pre-analysis sample tube closure LDPE inert to serum/plasma; no leaching into specimen
Research reagent tubes Buffer, reagent, stock solution tube archiving Stopper seals reusable glass and PS tubes between uses
Hematology / coagulation EDTA, citrate anticoagulant tube formats Color-coded stoppers for anticoagulant tube designation

Always validate stopper fit with your specific tube brand — 13 mm OD tubes vary in opening diameter by wall thickness. Request a free sample before bulk purchase.

Chemical Resistance — Low-Density Polyethylene (LDPE)

LDPE provides flexibility for friction-fit stopper retention and inertness to clinical specimen matrices.

Reagent / Condition Compatibility
Aqueous buffers / water ✓ Excellent
Urine / serum / plasma ✓ Excellent
Cell culture media ✓ Excellent
Dilute acids (<10%) ✓ Good
Dilute alkalies (pH <12) ✓ Good
Short-chain alcohols (brief) ✓ Good
DMSO (≤10%) ✓ Good — brief contact
Autoclave (121°C) ✗ Not compatible
Storage at -20°C ✓ Suitable — LDPE retains flexibility

Laboratory Applications

The serves microbiology culture tube programs, clinical chemistry and hematology tube archiving, and any laboratory requiring friction-fit sealed closure on 13 mm OD test tubes.

U.S. Manufacturing, Quality & Institutional Procurement

Every 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. Request a free sample below to validate fit before committing to volume.

Frequently Asked Questions — Caplugs® Evergreen

What tube formats use 13 mm OD and fit the stopper?

The fits 13 mm outer diameter test tubes, including: 13 × 75 mm and 13 × 100 mm glass and PS culture tubes, BD Vacutainer tube formats in 13 mm OD. Always validate fit with a sample before bulk purchase — opening diameter varies within the 13 mm OD range by wall thickness.

What is the clinical convention for yellow 13 mm tube stoppers?

Yellow stoppers mirror the CLSI H3 yellow-top SPS/ACD blood culture tube convention. For 13 mm tubes — which include many blood culture and specialized clinical tube formats — yellow stoppers designate SPS (Sodium Polyanethol Sulfonate) blood culture specimens and ACD (Acid Citrate Dextrose) specimen batches. All colors are identical in LDPE material and friction-fit performance.

Why is LDPE used for stopper caps rather than PP or PS?

Stopper-style caps work by friction fit — the plug must compress under insertion and spring back against the tube inner wall. PP and PS are too rigid for this and crack under repeated insertion/removal cycles. LDPE's low-density flex allows thousands of insertion cycles without fracture, retains flexibility at -20°C to prevent brittle failure, and provides chemical inertness to clinical specimen matrices.

View full details

Questions | Support?