Name: Graduated Stoppered Test Tube
Brand: RichTech

Specifications

Graduated Stoppered Test Tube · Specifications

The following are standard capacity options with commonly used diameter×length nominal values. Custom sizes are available upon request.

Request custom specs

Nominal Capacity (mL)	Common OD×Length (mm)	Graduation Interval (mL)	Packaging (pcs/case)	Material
5	13×100	0.5	500	Borosilicate 3.3
10	15×100 / 16×125	1.0	500	Borosilicate 3.3
15	16×150 / 18×150	1.0	500	Borosilicate 3.3
20	18×180 / 20×150	1.0	200	Borosilicate 3.3
25	20×200 / 25×150	1.0	200	Borosilicate 3.3
30	25×200 / 30×200	1.0	200	Borosilicate 3.3

* OD×Length are nominal values. Actual dimensions may vary slightly.
* Custom capacities and special sizes available upon request.

Sealing Technology: The ground glass stopper and tube mouth are precision-matched for consistent sealing performance. Each stopper is individually paired with its tube — do not interchange to maintain seal integrity.

Product Description

Graduated stoppered test tubes are versatile labware that combine accurate volume measurement with secure sealing functionality. Manufactured from high-quality borosilicate glass 3.3, these tubes feature permanent, precise graduations for rapid volume reading and a ground glass stopper for airtight sealing — preventing evaporation, oxidation, and contamination. This integrated design eliminates the need to transfer samples from graduated tubes to stoppered tubes, reducing handling steps and sample loss. Essential for standard solution preparation, sample aliquoting and storage, and reagent preservation in laboratories.

Key Features

Borosilicate Glass 3.3: ISO 3585 compliant · Low thermal expansion · Thermal shock resistance up to 280°C · Resistant to acids and alkalis
Precise Volume Graduations: Clear, permanent white enamel markings · Key volume points verified for accuracy
Ground Glass Stopper: Precision-ground for an airtight seal · Prevents evaporation and contamination
Dual-Function Design: Quantification and sealed storage in a single vessel — reduces sample transfer and loss
Superior Clarity: High-purity glass enables clear observation of sample state and meniscus
Autoclavable: 121°C / 15 psi / 20 minutes steam sterilization
Chemically Resistant: Compatible with acids, alkalis, salt solutions, and common organic solvents

Value Proposition: One tube = Graduated measurement + Sealed storage. Eliminates sample transfer between tubes — reduces handling, minimizes loss, and preserves sample integrity. Ideal for standard solution aliquoting, volatile sample storage, and precious reagent preservation.

Quality Assurance

Each graduated stoppered test tube undergoes rigorous dimensional inspection, graduation accuracy verification, and seal integrity testing. The white enamel markings are permanently fused to the glass surface, remaining legible through repeated washing and autoclaving cycles. Our products meet laboratory glassware quality standards.

Note: Graduations are intended for rapid estimation. For precise volumetric measurements, use calibrated volumetric flasks or pipettes. Stoppers are matched to individual tubes — do not interchange to ensure proper sealing. For long-term storage, place a small piece of lint-free paper between stopper and tube to prevent sticking.

Applications

Typical Application Areas

Standard Solution Preparation & Storage

Quantitative aliquoting and sealed preservation of standard materials

Volatile Sample Storage

Organic solvents, volatile reagents, flavors, and fragrances requiring airtight sealing

Precious Reagent Preservation

Accurate aliquoting and long-term sealed storage of expensive or scarce reagents

Sample Preparation

Environmental water samples, food extracts — quantitative collection and temporary sealed storage

Education

Quantitative experiments and sample preservation in university chemistry and biology courses

Pharmaceutical QC

Standard solution preparation, stability study sample aliquoting

Compliance & Standards

ISO Guide 80 — Guidance for the in-house preparation of quality control materials
ChP 0102 — Sample Preservation and Handling (Chinese Pharmacopoeia)
GB/T 6682 — Water for analytical laboratory use (compatible)

Tip: Graduated stoppered tubes are the functional combination of graduated tubes and stoppered tubes — ideal for applications requiring both quantitative dispensing and sealed storage. For best results, pair with RichTech volumetric flasks and pipettes for a complete sample management workflow.

Graduated Stoppered Test Tube Operation Guide

03

Preparation Before Use

Inspect tubes for cracks, chips, or rim damage
Verify stoppers fit properly — no wobbling or binding
Check that graduations are clear and legible
Wash with mild detergent and soft brush — rinse 3 times with distilled water
Autoclave at 121°C / 15 psi / 20 minutes

04

Quantitative Dispensing

Slowly pour or transfer liquid sample into the tube using a pipette or burette
Read volume at the bottom of the meniscus (standard graduated cylinder reading technique)
For precise adjustment to the graduation line, use a dropper to add or remove small volumes
Immediately secure the glass stopper after dispensing

05

Sealed Storage Procedure

Insert stopper vertically with a gentle twisting motion — avoid cross-threading
Verify seal integrity (invert or tilt to check for leakage)
Label clearly on the tube exterior (sample name, concentration, preparation date, expiry date)
Store in a cool, dry, light-protected location according to sample stability requirements

06

Sampling Procedure

Carefully remove the stopper — avoid excessive force that may damage the ground joint
Use a pipette or transfer pipette to withdraw the required volume
Reseal immediately after sampling to preserve sample integrity
Take care to avoid contaminating the sample or the stopper during handling

06

Cleaning & Maintenance

Clean immediately after use to prevent residue adhesion
Routine cleaning: Mild detergent + soft brush — rinse 3 times with distilled water
Stubborn residues: Soak in dilute nitric acid or specialized cleaning solution for 2–4 hours
Avoid strong alkaline cleaners or abrasive brushes that may damage graduations
Air dry inverted or place in oven at 60°C until dry
For extended storage, place a small piece of lint-free paper between stopper and tube to prevent sticking
Stoppers and tubes are matched pairs — do not interchange

Care & Notes

Show care & notes

Safety Precautions

Inspect for cracks or scratches before use — damaged tubes may break during heating or vacuum applications
When handling volatile, flammable, or toxic samples, work in a fume hood
Wear protective gloves and goggles when handling strong acids and alkalis
When storing alkaline samples long-term, consider using PTFE stoppers to prevent ground joint sticking

Do not

Stoppers are individually paired with each tube — do not interchange