Laboratory Erlenmeyer flasks: for which mixing and culture applications are they used?

An icon of the lab, the Erlenmeyer flask pairs a stable conical body with a narrow neck to mix, dissolve and culture without splashing. In chemistry and the life sciences alike, it excels on orbital shakers for suspension culture, medium aeration and solution prep. Reusable borosilicate 3.3 glass, sterile PETG or autoclavable polycarbonate, baffled versions and 0.2 µm vented caps: each option optimises oxygen transfer, clarity or chemical resistance. From 50 mL to 5 L, graduated, compatible with clamps and glassware washers, the Erlenmeyer remains a reliable, precise and versatile choice.

What are the different types of Erlenmeyer flasks?

With a design optimised for controlled mixing, the Erlenmeyer flask comes in three main families.

• Glass Erlenmeyer (borosilicate 3.3): reusable, highly resistant to thermal shock and solvents. Ideal for heating, titrations, synthesis and storage. Narrow neck limits evaporation, stable flat base, clear graduations. Autoclavable and glasswasher-compatible.

• Plastic Erlenmeyer: PETG (very transparent, gamma-sterilised, non-autoclavable), polycarbonate (robust, autoclavable 121 °C), sometimes PP (autoclavable, less transparent). Often supplied sterile, ready to use, and fitted with 0.2 µm filter-membrane caps to enhance gas exchange for shaker cultures.

• Cell culture Erlenmeyer: smooth or baffled versions (internal ridges) to increase turbulence, kLa and oxygenation. Baffles boost microbial growth (yeasts, E. coli) but may raise shear forces for sensitive animal cells; in that case choose non-baffled flasks and vented caps.

Selection criteria: chemistry/solvents, need for sterility, temperature (heating/autoclave), oxygen transfer, working volume (20–35% of nominal volume on a shaker), compatibility with clamps/racks, accuracy of graduations, labelling/marking, cap (solid, filter/vented, PTFE, septum), narrow or wide neck for pipetting ease.

Type	Key principle	Applications
Borosilicate glass 3.3	Reusable, chemical/thermal resistance, direct heating	Chemistry, titrations, synthesis, storage, teaching
PETG/PC plastic	Sterile, ready to use; PC autoclavable, PETG very transparent	Microbiology, cell culture, sterile preparations
Culture (baffled/non-baffled)	Baffles ? turbulence/OTR; non-baffled ? shear	Microbial screening, CHO/HEK in suspension, media optimisation

In which fields is a conical (Erlenmeyer) flask used?

In biotechnology and pharmaceuticals, the Erlenmeyer flask is a go-to for upstream work: inoculation, media optimisation, strain screening, and scalability studies ahead of the bioreactor. In microbiology, it’s used for shaker cultures (yeasts, bacteria) and aeration tests. In cell culture (CHO, HEK in suspension), sterile flasks with a vented cap promote growth in an orbital shaker incubator. In analytical chemistry, it enables safe titrations, dilutions and extractions. QC laboratories and agri/environment use it for sample preparation, COD/BOD measurements, shaking extracts and stability testing. In education, its robustness and easy-to-read graduations make it a classroom staple.

The different types of Erlenmeyer flasks available

Frequently asked questions about Erlenmeyer flasks

Glass or plastic: how to choose?
For solvents/heating, choose borosilicate glass. For sterile culture and time savings, PETG/PC. Use PC if autoclaving is required; pick PETG for gamma sterility and high optical clarity.

Baffled or unbaffled for culture?
Baffles increase turbulence and the oxygen transfer rate (OTR), ideal in microbiology. Unbaffled versions limit shear, preferable for sensitive cells.

What fill volume on an orbital shaker?
As a rule of thumb, 20–35% of the nominal volume to optimise aeration without splashing. Adjust to speed, orbit and medium viscosity.

Which caps should you choose?
For culture: vented caps or 0.2 µm filter caps for gas exchange. For chemistry/storage: solid caps; PTFE-lined or septum closures depending on solvents and analyses.

Is PETG autoclavable?
No. PETG is gamma-sterilised and does not tolerate autoclaving. Choose polycarbonate (PC) or glass for autoclaving at 121 °C.

How to limit contamination?
Use sterile bottles, work in a microbiological safety cabinet (MSC), favour filter caps, minimise openings and use sterile, shaker-compatible accessories.

Is there an environmental impact?
Glass is reusable and recyclable but consumes water and energy during cleaning. Plastics reduce cleaning validation effort, yet generate more waste to process.