The Technical Vault
By SOSCleanroom
KIMBLE 60B12BZW
MARK-M
5 mL
12 x 75 mm
51 Expansion Glass
USP Type I
ASTM Type I Class B
White Ceramic Label
1-3/8 in Vertical
250 / Shelf Pack
1000 / Case
Technical overview: MARK-M glass culture tubes with permanent identification areas
KIMBLE® MARK-M™ 60B12BZW is a 5 mL nominal clear borosilicate culture tube measuring 12 mm outside diameter x 75 mm length. Its defining feature is a permanent white 1-3/8-inch vertical ceramic marking area fused to the exterior of the glass tube.
The ceramic label is located approximately 3/4 inch below the open end and is designed to accept writing with a laboratory marker or pencil. The marking area supports sample identification without requiring a separately applied adhesive label.
DWK describes the glass as borosilicate 5.1. The KIMBLE Biological Science Guide identifies the corresponding glass family as 51-expansion borosilicate, conforming to USP Type I and ASTM E438 Type I, Class B requirements.
The manufacturer supplies 250 tubes per shelf pack and 1,000 per case. The tube is intended for general laboratory use where the material, physical dimensions, and marking configuration are appropriate.
Technical takeaway: Order 60B12BZW for the 5 mL, 12 x 75 mm, white 1-3/8-inch vertical-label version. The ceramic marking area is for sample identification, not calibrated volume measurement. Closures are not included.
Technical specifications and purchasing identification
- Manufacturer: DWK Life Sciences
- Brand: KIMBLE® MARK-M™
- Manufacturer Catalog Number: 60B12BZW
- Product: Borosilicate glass culture tube with permanent ceramic marking area
- Nominal Capacity: 5 mL
- Glass Material: Borosilicate glass 5.1 / 51 expansion
- Glass Classification: USP Type I
- ASTM Classification: ASTM E438 Type I, Class B
- Tube Color: Clear
- Outside Diameter: 12 mm
- Overall Tube Length: 75 mm
- Marking Type: Permanent fused ceramic label
- Marking Color: White
- Marking Orientation: Vertical
- Marking Length: 1-3/8 inch, approximately 34.9 mm
- Marking Position: Approximately 3/4 inch from open end
- Writing Medium: Marker or pencil
- Bottom Construction: Sturdy, uniform bottoms per DWK
- Bottom Shape: Round bottom per independent exact-SKU product records
- Closure Included: No
- Graduations: No calibrated scale specified
- Volumetric Accuracy: Not specified
- Supplied Sterility: Nonsterile per independent exact-SKU product records
- Manufacturer Shelf Pack: 250 tubes
- Manufacturer Case: 1,000 tubes
- Purchase Unit: Case
- Validated Centrifuge Rating: Not established
- Validated Autoclave Cycle: Not established for this SKU
The nominal dimensions and capacity are manufacturer specifications. The current product listing does not establish a calibrated volumetric tolerance, confirmed inner diameter, wall-thickness tolerance, sterile processing claim, or finished-product temperature rating.
51-expansion borosilicate glass: USP Type I versus ASTM Type I Class B
DWK describes this tube as manufactured from borosilicate glass 5.1, also described in its technical catalog as 51-expansion borosilicate glass. The material conforms to manufacturer-stated USP Type I and ASTM E438 Type I, Class B requirements.
These material specifications are important because they distinguish the tube from common soda-lime glass and from 3.3-expansion ASTM E438 Type I Class A borosilicate glass.
| Characteristic |
60B12BZW |
Selection implication |
| Glass family | Borosilicate | Not soda-lime |
| Expansion designation | 51 / 5.1 | Not 33 / 3.3 |
| USP glass type | Type I | Material classification |
| ASTM E438 | Type I, Class B | Not Class A |
| Glass color | Clear | No stated amber shielding |
USP Type I and ASTM E438 Type I Class B are not interchangeable classification systems. Although multiple borosilicate compositions can satisfy a USP Type I designation, their thermal expansion and other physical properties may differ.
Glass selection rule: Do not transfer material properties, temperature ratings, or physical constants from a 3.3-expansion Class A product to this 51-expansion Class B tube without supporting data.
Permanent ceramic writing area: construction and identification function
KIMBLE MARK-M tubes incorporate a permanent ceramic marking area fused directly to the glass. This differs from separately applied adhesive paper labels or removable sleeves.
The white marking surface provides a contrasting area for handwritten identification using compatible laboratory markers or pencils. The manufacturer does not designate the marking area as a calibrated graduation or as a preprinted barcode.
- Marking Material: Ceramic surface permanently fused to glass
- Color: White
- Orientation: Vertical
- Length: 1-3/8 inches, approximately 34.9 mm
- Position: 3/4 inch below the open end
- Recommended Writing Media: Marker or pencil
- Primary Function: Sample and tube identification
- Volume Markings: No graduated volume scale specified
- Barcode or Serialization: Not supplied as a verified SKU feature
The ceramic surface is permanent, but the durability of handwriting placed on it depends on the marker, solvent exposure, abrasion, and cleaning procedure. A fused ceramic marking field does not establish that every ink will remain legible after all cleaning or sterilization methods.
1-3/8-inch vertical label versus 3/4-inch banded label
DWK offers two different ceramic marking configurations in the KIMBLE MARK-M family. Both are permanently fused to the glass, but their dimensions and orientation are different.
The 60B12BZW uses a white 1-3/8-inch vertical marking area. The separately listed 60B12BZXW uses a white 3/4-inch banded marking area. Both have the same nominal 5 mL capacity and 12 x 75 mm dimensions.
| Specification |
60B12BZW |
60B12BZXW |
| Label style | Vertical | Banded |
| Label length | 1-3/8 in | 3/4 in |
| Label color | White | White |
| Tube capacity | 5 mL | 5 mL |
| Dimensions | 12 x 75 mm | 12 x 75 mm |
| Case quantity | 1,000 | 1,000 |
Selection checkpoint: The two tubes share capacity and dimensions, but their writable ceramic areas differ. When a laboratory specifies vertical marking, order 60B12BZW rather than the banded 60B12BZXW.
5 mL nominal capacity versus calibrated liquid measurement
The manufacturer's 5 mL capacity is a nominal product-size designation. DWK does not specify a certified graduation, calibrated tolerance, or exact brimful volume for this MARK-M tube.
The white marking field is for identifying samples and does not provide an accurate volume scale. Laboratories needing to measure or dispense precise liquid amounts should use properly selected volumetric glassware or calibrated pipetting equipment.
- Nominal Capacity: 5 mL
- Calibrated Capacity: Not specified
- Working Volume: Dependent on the laboratory procedure
- Brimful Capacity: Not specified
- Graduation Interval: No volume graduations specified
- Certified Tolerance: Not specified
- Fill-Level Control: Determine according to sample and method requirements
Measurement limitation: Do not advertise this tube as a calibrated 5 mL measuring instrument. Its purpose is sample containment and identification, not precision volume measurement.
Research, culture, and routine laboratory sample applications
The MARK-M line is designed for general laboratory culture-tube applications. Its permanent ceramic identification area makes the tube useful where samples need to be clearly marked during handling, testing, observation, or laboratory storage.
Possible uses include compatible research samples, culture-tube procedures, analytical laboratory work, sample organization, educational laboratories, and quality-control operations. Actual suitability must be established by the user's method.
- Sample Identification: Record sample or batch information directly on the ceramic marking area.
- Laboratory Culture Procedures: Use after meeting applicable cleanliness, sterility, and closure requirements.
- Research Workflows: Contain compatible small-volume liquids or other laboratory samples.
- Quality Control: Assist with handwritten sample tracking and organization.
- Teaching Laboratories: Use in suitable instructional procedures.
- Sample Observation: Clear glass allows visual assessment of contents.
The term "culture tube" does not establish that the item is supplied sterile or that it is qualified for every cell-culture or microbiological process. Use appropriate facility preparation and contamination-control procedures.
Tube opening, bottom geometry, and closure compatibility
The manufacturer specifies the tube's outside diameter, length, and permanent ceramic marking area but does not include a matching cap or stopper with 60B12BZW. Independent exact-SKU records describe the product as an open, round-bottom culture tube.
Distributor descriptions differ concerning the detailed opening or rim terminology. Therefore, a specific rim design or standardized screw-thread finish should not be assigned without current manufacturer documentation.
- Tube Opening: Open laboratory culture tube
- Manufacturer-Listed OD: 12 mm
- Tube Bottom: Round bottom according to independent exact-SKU descriptions
- Manufacturer Feature: Sturdy, uniform bottoms and consistent lengths
- Closure Included: No
- Thread Finish: None established for this SKU
- Closure Size: Not established by the current product listing
- Seal Integrity: No seal rating applicable to the unclosed supplied tube
Closure selection rule: Do not assume that a general-purpose 12 mm cap or stopper is compatible based only on tube OD. Verify actual mouth geometry and the closure manufacturer's fit specifications before purchasing accessories.
Borosilicate chemical resistance and sodium leaching
DWK identifies resistance to sodium leaching as a benefit of its borosilicate glass tubes. This is relevant when a laboratory is selecting a glass material for sample handling and wants to reduce potential interference associated with glass composition.
However, DWK does not provide a quantitative sodium-release result for 60B12BZW. A general material statement must not be treated as a certified elemental blank or a guaranteed non-leaching result under all laboratory conditions.
Glass resistance depends on chemical composition, concentration, temperature, and exposure time. Borosilicate glass has broad chemical durability but important limitations with certain aggressive reagents, including hydrofluoric acid and strong alkaline conditions.
- Glass Type: 51-expansion borosilicate
- Manufacturer-Described Benefit: Resistance to sodium leaching
- Specific Leach Limit: Not established
- Analytical Background: Evaluate with method-specific blank testing if required
- Chemical Compatibility: Determine for each reagent and operating condition
- Temperature: Can affect chemical attack and material durability
- Storage Time: Extended contact may require additional qualification
Analytical limitation: Do not claim zero sodium release, certified trace-element cleanliness, universal chemical inertness, or complete resistance to aggressive reagents without supporting product-specific testing.
Sterility, pre-cleaning, and laboratory preparation
Independent exact-SKU distributor records identify KIMBLE 60B12BZW as nonsterile. The current DWK product page does not state that the product is supplied sterile, gamma irradiated, ethylene-oxide sterilized, or aseptically packaged.
The presence of a permanent ceramic marking surface does not establish biological cleanliness. No product-specific limits for particles, endotoxin, RNase, DNase, or microbial contamination are established by the reviewed SKU record.
- Supplied Sterility: Nonsterile according to exact-SKU distributor records
- Sterile Barrier Packaging: Not specified
- Gamma Sterilization: Not specified
- Ethylene Oxide Sterilization: Not specified
- Depyrogenation: Not specified
- Pre-Cleaned Analytical Status: Not specified
- RNase/DNase Limits: Not specified
- Required Preparation: Determine according to laboratory SOP and intended application
For contamination-sensitive applications, inspect and process tubes according to the laboratory's validated cleaning or sterilization procedures. Current manufacturer instructions should be consulted before adopting any specific thermal or chemical process.
Glassware cleaning and inspection procedures
DWK's general laboratory-glassware care guidance recommends inspecting glassware for damage and applying appropriate cleaning practices before use. Selection of the cleaning chemistry depends on the glass material and intended test.
- Inspect: Check for chipped openings, cracks, scratches, damage, and visible foreign material.
- Inspect the Marking Area: Confirm the white ceramic label is intact and appropriate for the intended identification procedure.
- Clean: Apply a laboratory-approved cleaning procedure compatible with the glass material.
- Rinse: Use an appropriate rinsing medium when required by the method.
- Dry: Avoid contamination, excessive thermal shock, and mechanical damage.
- Identify: Apply sample information with the appropriate marker or pencil.
- Prepare for Use: Meet any additional sterility, blank-test, or handling requirements.
- Handle Safely: Use suitable racks and avoid unnecessary glass-to-glass contact.
If a procedure includes cleaning after handwriting has been applied, confirm that the writing remains legible and that marking materials do not contaminate the sample.
Thermal processing, autoclaving, and temperature limitations
Borosilicate glass is commonly selected for laboratory applications involving temperature changes. However, DWK's current 60B12BZW product page does not specify a validated autoclave cycle, maximum use temperature, thermal shock rating, or cryogenic operating range for this exact tube.
The product is 51-expansion Class B glass, and data for unrelated 3.3-expansion Class A glassware should not automatically be transferred to this SKU.
- Glass: 51-expansion borosilicate
- Validated Autoclave Cycle: Not established for this SKU
- Maximum Temperature: Not individually specified
- Thermal Shock Limit: Not individually specified
- Freezer/Cryogenic Rating: Not established
- Closure During Heating: Requires separate evaluation if one is added
- Writing Durability: Marker/pencil performance under heating not verified
Thermal safety: Do not publish a guaranteed 121-degree-C autoclave cycle, maximum processing temperature, or rapid-temperature-change tolerance without a current manufacturer recommendation and appropriate process qualification.
Centrifugation and equipment compatibility
DWK identifies the MARK-M product as a culture tube, not as a manufacturer-rated centrifuge tube. No maximum relative centrifugal force (RCF), rotor compatibility, or operating speed has been established for 60B12BZW.
A physical fit within a centrifuge adapter, test-tube rack, or other instrument does not establish mechanical suitability or resistance to acceleration and vibration.
Equipment qualification: Do not transfer centrifugal-force specifications from KIMBLE 73790, 73785, or other dedicated centrifuge-tube families to this MARK-M culture tube. Use manufacturer-rated tubes where centrifugation is required.
MARK-M 5 mL vertical-label variants: white, blue, green, and yellow
DWK offers the 5 mL / 12 x 75 mm borosilicate MARK-M tube with multiple ceramic marking colors. The marking color is a product-selection characteristic and can be incorporated into laboratory identification procedures.
| SKU |
Color |
Capacity |
Case |
| 60B12BZB | Blue | 5 mL | 1,000 |
| 60B12BZG | Green | 5 mL | 1,000 |
| 60B12BZL | Yellow | 5 mL | 1,000 |
| 60B12BZW | White | 5 mL | 1,000 |
All four variants have the same manufacturer-listed capacity and overall dimensions, but the color of the ceramic marking area differs. Label color does not independently indicate sample chemistry, sterility, additive content, or the intended culture medium.
Image accuracy: A photograph of 60B12BZG illustrates the green-label version, not this white-label 60B12BZW product. Verify product imagery against the complete manufacturer part number.
Other MARK-M 1-3/8-inch vertical-label tube sizes
The KIMBLE MARK-M vertical-label family includes additional nominal capacities and physical sizes. Select the exact catalog number where outside diameter, length, marking color, or nominal capacity are important.
| SKU |
Capacity |
Dimensions |
Color |
| 60A10BZW | 3 mL | 10 x 75 mm | White |
| 60B12BZW | 5 mL | 12 x 75 mm | White |
| 60C13BZW | 9 mL | 13 x 100 mm | White |
| 60E16BZW | 14 mL | 16 x 100 mm | White |
These products have different physical dimensions and are not necessarily interchangeable with racks, stoppers, instruments, or approved laboratory methods. Verify exact attributes before substitution.
250-count shelf packs and 1,000-count manufacturer cases
DWK's current product record lists 250 tubes per shelf pack and 1,000 tubes per case. These represent two packaging levels. The standard purchase unit in SOSCleanroom's supplier setup is the manufacturer case.
| Packaging level |
Quantity |
Notes |
| Individual tube | 1 | Unclosed glass tube |
| Shelf pack | 250 | Manufacturer inner packaging designation |
| Case | 1,000 | Standard listed purchase unit |
Purchasing checkpoint: A 250-count shelf pack is a manufacturer inner-pack quantity and should not automatically be treated as the standard online selling unit. Confirm whether smaller quantities are separately available before quoting them.
Receiving and quality-inspection checklist
For receiving and laboratory release, verify the exact manufacturer SKU and the white marking configuration. Related MARK-M variants can have identical tube dimensions but different colors or marking geometry.
- Verify Part Number: Confirm 60B12BZW on packaging and documents.
- Confirm Capacity: Nominal 5 mL.
- Confirm Dimensions: 12 mm OD and 75 mm length.
- Confirm Glass: Borosilicate 5.1 / 51 expansion.
- Confirm Marking: White 1-3/8-inch vertical ceramic label.
- Inspect Writing Areas: Check for missing, damaged, or irregular ceramic markings.
- Inspect Glass: Check for cracks, chips, scratches, or broken tubes.
- Confirm Case Quantity: 1,000 tubes per case, with 250 per shelf pack.
- Check Closures: No included cap or stopper expected for the standard configuration.
- Determine Preparation: Apply any required washing, sterility, or analytical blank controls before use.
- Document Exceptions: Quarantine incorrect color, dimensions, or damaged goods according to quality procedures.
If a manufacturer's image filename references the green-label version, inspect the product photograph and verify its appearance before publishing it as the white-label SKU.
Storage and handling of empty glass culture tubes
The DWK supplier item-setup record lists room-temperature shipping and storage for these empty tubes. Store in conditions that protect the glass from impact, excessive vibration, moisture damage to packaging, and avoidable contamination.
- Keep unused tubes in appropriate protective packaging until needed.
- Avoid loose handling that causes tubes to strike one another.
- Inspect glass and marking areas before use.
- Follow approved procedures for cleaning and preparation.
- Protect any separately applied handwriting from incompatible solvents or abrasion.
- Determine storage requirements for filled tubes based on their actual contents.
The storage condition of the empty glass product is not a sample-stability specification. Filled laboratory tubes may require refrigeration, freezing, light protection, or other controls that depend on the sample.
Technical FAQs
What is KIMBLE 60B12BZW?
A 5 mL clear borosilicate culture tube with a white 1-3/8-inch vertical ceramic marking area, measuring 12 x 75 mm.
What is the nominal capacity?
5 mL. This is a manufacturer size designation, not a certified volume tolerance.
What material is the tube made from?
51-expansion borosilicate glass, referred to as borosilicate glass 5.1 by DWK.
What glass standards apply?
DWK's KIMBLE technical guide states USP Type I and ASTM E438 Type I, Class B.
Is this 3.3-expansion borosilicate glass?
No. It is 51-expansion, ASTM Type I Class B glass rather than 3.3-expansion Class A.
Is the marking area vertical?
Yes. The white marking area is a permanent 1-3/8-inch vertical ceramic label.
How far below the opening is the label?
Approximately 3/4 inch from the open end.
Can I write on the ceramic label?
Yes. DWK describes the surface as writable using a marker or pencil.
Does the marking area show volume graduations?
No. It is an identification area rather than a calibrated measuring scale.
How is this different from 60B12BZXW?
60B12BZXW uses a white 3/4-inch banded marking area. Both products are 5 mL and 12 x 75 mm, but the ceramic label configurations differ.
Is 60B12BZG the same item?
No. It is the green vertical-label version. This 60B12BZW product has a white label.
Are these tubes supplied sterile?
Independent exact-SKU distributor records identify them as nonsterile. DWK does not specify a sterile designation on its current product listing.
Are caps or stoppers supplied?
No matching closure is included in the confirmed distributor descriptions. Any required closure must be selected separately and checked for compatibility.
Are the tubes round-bottom?
Independent exact-SKU product records identify a round bottom. DWK describes sturdy, uniform bottoms but does not resolve all distributor rim terminology.
Are the tubes rated for centrifugation?
No manufacturer-verified centrifugal-force rating is established for 60B12BZW.
Can the tubes be autoclaved?
No SKU-specific validated autoclave cycle was established by the reviewed manufacturer listing. Request current technical guidance for the intended processing method.
Does borosilicate glass resist sodium leaching?
DWK identifies sodium-leaching resistance as a material benefit. A quantitative SKU-specific sodium-release limit is not provided.
What is the manufacturer shelf-pack quantity?
250 tubes.
How many tubes are in a case?
1,000 tubes.
Does white marking indicate a sterile product?
No. White is the ceramic marking color, not a sterility designation or additive specification.
Can these tubes be used for precise 5 mL measurement?
No calibrated volumetric tolerance is established. Select a calibrated measuring instrument when the method requires precision.
Manufacturer technical documentation and reference materials
General technical guides explain glass chemistry, laboratory handling, and material selection. They do not establish individual sterility certificates, verified centrifuge ratings, quantitative leach testing, or universal chemical compatibility for this product.
Why SOSCleanroom? Our team can help laboratories identify the correct KIMBLE MARK-M tube size, ceramic label configuration, borosilicate glass classification, case quantity, and available manufacturer documentation.
For technical questions, formal quotations, or current availability, contact Sales@SOSsupply.com or call (214) 340-8574.
Last updated: October 29, 2026
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