The Use and Care of PyrexPlus® Laboratory Glassware

PyrexPlus labware is designed to offer
additional safety and protection, plus extended product life,
by coating the exterior surface with a PVC polymer.

Autoclaving    Cleaning     Exposure to...     Labeling and Marking
Cleaning Specific Types of Pyrex Glassware
General Use and Care Recommendations


PyrexPlus labware can be successfully sterilized using liquid or dry cycle sterilization which involves no vacuum or low vacuum (5 inches Hg).

Recommended cycles for automated autoclaves are:

Autoclave cycle Autoclave type
Gravity Prevacuum
Liquid Yes Yes
Dry Yes No
Prevacuum No

CAUTION: Always autoclave vessels with loose caps or closures.

Sterilization time should not exceed 15 minutes at 121°C (250°F). Drying time should not exceed 15 minutes at 110°C (230°F). The actual cavity temperature of the autoclave should be checked to be sure the autoclave temperature does not exceed the recommended sterilization and drying temperature.

Autoclaving—Cloudiness: Should the coating appear clouded due to dissolved moisture, simply let dry overnight at room temperature or briefly heat to 110°C (230°F).


As is common practice, clean all glassware before use. Any non-abrasive glassware detergent may be used for hand or automatic dishwasher cleaning. If using a dishwasher or glassware dryer, care should be taken to be sure the drying temperature does not exceed 110°C (230°F). Exposure to dry heat should be minimized.

Avoid brushes and cleaning pads which could abrade the glass or damage the coating. If using a chromic acid cleaning solution minimize contact of the solution with the coating.

Exposure to...

Exposure to Chemicals
As with all Pyrex brand borosilicate glass labware, the PyrexPlus vessel has excellent chemical inertness. The coating, however, is designed to resist leakage resulting from a brief chemical exposure that might occur if the vessel is broken. Prolonged and/or repeated chemical exposure of the coating to aldehydes, ketones, chlorinated solvents and concentrated acids should be avoided.

Exposure to Cold
PyrexPlus labware should not be exposed to temperatures below -20°C (-4°F). Extremely low temperatures may result in the coating becoming cracked. Exposure to temperatures below room temperature (23°C or 73°F) can temporarily reduce the ability of the coating to contain its contents if the vessel is broken.

Exposure to Heat
PyrexPlus labware is designed to withstand the temperatures associated with steam sterilization. However, it should not be placed over direct heat or an open flame. Prolonged exposure to dry heat may also cause the coating to become brittle and thereby reduce the useful life of the vessel. A brown appearance or hardness to the touch are signs that the coating has become brittle. The upper temperature limit for PyrexPlus labware is 110°C (230°F). PyrexPlus labware should not be exposed to elevated temperatures in a vacuum greater than 5 inches Hg (127 mm Hg).

Exposure to Microwave
PyrexPlus labware is completely microwave safe. However, as with any microwave vessel, be sure there is a load (water or other microwave absorbing material) in the microwave oven. Also, be sure all caps and closures are loosened.

Exposure to Ultraviolet
Prolonged and/or repeated exposure of the PyrexPlus labware coating to direct sunlight or ultraviolet sources (such as sterilization lamps) is not recommended.

Exposure to Vacuum
PyrexPlus containers (such as filter flasks and aspirator bottles) have demonstrated the ability to contain glass fragments upon implosion at room temperature. However, in keeping with safe laboratory practice, always use a safety shield around evacuated containers.

Labeling and Marking

Use water-based markers for temporary marking or labeling of the PyrexPlus labware coating. Solvent-based markers, dyes and stains cannot be removed from the coating.

NOTE: A slight "plastic" odor may be detected when handling PyrexPlus labware. This is due to additives in the plastic coating which are responsible for its superior performance. The odor is normal and will not affect the inertness of the inside borosilicate glass surface.

Cleaning Specific Types of Pyrex Glassware

Remove the stopcock or rubber tip and wash the buret with detergent and water. Rinse with tap water until all the dirt is removed. Then rinse with distilled water and dry. Wash the stopcock or rubber tip separately. Before a glass stopcock is placed in the buret, lubricate the joint with stopcock lubricant. Use only a small amount of lubricant. Burets should always be covered when not in use.

Culture Tubes
Culture tubes which have been used previously must be sterilized before cleaning. The best method for sterilizing culture tubes is by autoclaving for 30 minutes at 121°C (15 psi pressure). Media which solidifies on cooling should be poured out while the tubes are hot. After the tubes are emptied, brush with detergent and water, rinse with distilled water, place in a basket and dry.

If tubes are to be filled with a media which is sterilized by autoclaving, do not plug until the media is added. Both media and tubes are thus sterilized with one autoclaving.

If the tubes
are to be filled with sterile media, plug and sterilize the tubes in the autoclave or dry air sterilizer before adding the media.

Dishes and Culture Bottles
Sterilize and clean as detailed under Culture Tubes (above). Wrap in heavy paper or place in a petri dish can. Sterilize in the autoclave or dry air sterilizer.

Serological Tubes
Serological tubes should be chemically clean, but need not be sterile. However, specimens of blood which are to be kept for some time at room temperature should be collected in a sterile container. It may be expedient to sterilize all tubes.

To clean and sterilize tubes containing blood, discard the clots in a waste container and place the tubes in a large basket. Put the basket, with others, in a large bucket or boiler. Cover with water, add a fair quantity of soft soap or detergent and boil for 30 minutes. Rinse the tubes, clean with a brush, rinse, and dry with the usual precautions.

It is imperative when washing serological glassware that all acids, alkali, and detergents be completely removed. Acids, alkali, and detergents in small amounts interfere with serologic reactions.

Serologic tubes and glassware should be kept separate from all other glassware and used only for serologic procedures.

Slides and Cover Glass
It is especially important that microscope slides and cover glass used for the preparation of blood films or bacteriologic smears be perfectly clean and free from scratches.

Slides should be washed, placed in glacial acetic acid for 10 minutes, rinsed with distilled water, and wiped dry with clean paper towels or cloth. Once the slides have been washed, place them in a wide jar of alcohol. As needed, remove from the jar and wipe dry. If the slides are dry stored, wash them with alcohol before use.

Place pipets, tips down, in a cylinder or tall jar of water immediately after use. Do not drop them into the jar. This may break or chip the tips and render the pipets useless for accurate measurements. A pad of cotton or glass wool at the bottom of the jar will help to prevent breaking of the tips. Be certain that the water level is high enough to immerse the greater portion or all of each pipet.

The pipets may then be drained and placed in a cylinder or jar of dissolved detergent or, if exceptionally dirty, in a jar of chromic acid cleaning solution. After soaking for several hours, or overnight, drain the pipets and run tap water over and through them until all traces of dirt are removed. Soak the pipets in distilled water for at least one hour. Remove from the distilled water, rinse, dry the outside with a cloth, shake the water out and dry.

Blood Cell Count Diluting Pipets
After use, rinse thoroughly with cool tap water, distilled water, alcohol, or acetone, and then ether.

Dry by suction. Do not blow into the pipets as this will cause moisture to condense on the inside of the pipet.

To remove particles of coagulated blood or dirt, a cleaning solution should be used. One type of solution will suffice in one case, whereas a stronger solution may be required in another. It is best to fill the pipet with the cleaning solution and allow to stand overnight. Sodium hypochlorite (laundry bleach) or a detergent may be used. Hydrogen peroxide is also useful. In difficult cases, use concentrated nitric acid. Some particles may require loosening with a horse hare or piece of fine wire. Take care not to scratch the inside of the pipet.

Automatic Pipet Washers
Where a large number of pipets are used daily, it is convenient to use an automatic pipet washer. Some of these, made of metal, can be connected directly by permanent fixtures to the hot and old water supplies. Others, such as those made with polyethlyene, can be attached to the water supplies by rubber hose. Polyethylene baskets and jars may be sued for soaking and rinsing pipets in chromic acid cleaning solution. Electrically heated metallic pipets dryers are also available.

After drying, place pipets in a dust-free drawer. Wrap serologic and bacteriologic pipets in paper or place in pipet cans and sterilize in the dry air sterilizer. Pipets used for transferring infectious material should have a cotton plug placed in the top end of the pipet before sterilizing. The plug will present the material being drawn accidentally into the pipetting device.

General Use and Care Recommendations

  • Proper care and handling of PyrexPlus labware or any labware will greatly increase its life and increase the safety of your work place.
  • Do not place PyrexPlus labware over direct heat or open flame.
  • The recommended temperature use range for PyrexPlus labware is 10°C to 80°C.
  • Do not continuously expose PyrexPlus labware to heat above 80°C.
  • Do not expose to dry heat in dishwasher above 110°C (230°F). Drying time should not exceed 15 minutes at 110°C (230°F).
  • Do not autoclave above 121°C (250°F). Sterilizing time should not exceed 15 minutes.
  • Do not refrigerate below -20°C (-4°F).
  • Do not remove the protective coating. Do not
  • use a vessel on which the coating is hardened, darkened or otherwise damaged.
  • Do not use PyrexPlus labware to store
  • hazardous chemical below room temperature.
  • Do not allow prolonged or repeated exposure
  • of the coating to strong acids or solvents.
  • Do not use a vessel once the glass is broken, immediately transfer the contents of a broken vessel to an approved container and properly
  • dispose of the broken vessel.
  • Do not incinerate discarded vessels. Place in proper disposal containers.

Disclaimer: Cole-Parmer products are not approved or intended for, and should not be used for medical, clinical, surgical or other patient-oriented applications.