Laboratory Incubators: Types, Applications, and How to Choose

Thelaboratory incubator is a fundamental tool in scientific research and industry. It is a completely isolated environment, designed to maintain stable and controlled temperature and humidity conditions, essential for the growth of microorganisms, cell cultures, and biological tissues.

In this guide we will delve into how the incubator works, the different types available, the applications by sector and the criteria for choosing the most suitable model for your laboratory.

What is Incubation and Why Do You Need an Incubator?

In zoology, incubation is defined as the initial stage of an organism's development, typically the growth of an embryo inside an egg.Laboratory incubation aims to artificially reproduce the conditions that govern this process.

In scientific laboratories, incubation is primarily used to grow bacteria, yeasts, cells, and tissues. This requires an isolated environment that simulates typical incubation conditions: constant temperature, relative humidity , and, in some cases, a modified atmosphere.

How a Laboratory Incubator Works

Laboratory incubators are environments designed to ensure the stability and precision of internal conditions. The two fundamental parameters to regulate are temperature and relative humidity .

Thanks to PID control systems, it is possible to set pre-set values ​​and maintain them unchanged for long periods of time. The typical temperature range is from ambient +5°C to +100°C, with stability of ±0.1°C in the most precise models.

Some incubators are able to provide special atmospheric conditions, such as an oxygen-free or carbon dioxide-enriched atmosphere, to meet specific cell growth needs.

Types of Incubators

There are different types of laboratory incubators, each designed for specific applications:

Natural Convection Incubator

The simplest model. Heat is distributed by natural convection, without forced ventilation. Ideal for delicate cell cultures that cannot tolerate air movement. Typical range: ambient +5°C to +80°C.

Forced Convection Incubator

Equipped with an internal fan for even heat distribution. It offers superior thermal uniformity and faster recovery times after opening the door. Suitable for stability testing and applications requiring uniformity throughout the cabinet.

CO₂ incubator

A specialized incubator with controlled CO₂ concentration (typically 5%). Essential for growing mammalian cells and biological tissues that require a controlled atmosphere. For more information, read our article on CO₂ growth chambers.

Refrigerated Incubator

Combines heating and active cooling, allowing operation even below ambient temperature. Typical range: +5°C to +100°C. Required for BOD (Biological Oxygen Demand) applications and low-temperature microbiological testing.

For advanced applications requiring controlled CO2 atmospheres_in addition to standard thermoregulation, FDM produces a test chamber_CO2 designed for biotechnology, pharmaceutical, and research laboratories.

Applications by Sector

The uses of incubators are extremely diversified:

• Pharmaceutical and medical: cell and tissue culture, drug stability testing, incubation of microbiological samples for quality control
• Agri-food: microbiological analysis of foods, bacterial colony counting, shelf-life testing
• Cosmetics and chemicals: accelerated stability testing on cosmetic formulations, cultivation of microorganisms for preservative efficacy testing
• Scientific research: cellular and molecular biology, bacterial metabolism studies, tissue regeneration, temperature-controlled experiments

How to Choose the Right Incubator

The choice of incubator depends on four main factors:

• Temperature range: For applications above chamber temperature, a standard incubator is sufficient. For operations below 20°C, a refrigerated model is required.
• Atmospheric control: If controlled levels of CO₂ or O₂ are required, a CO₂ incubator or specialized chamber is required
• Internal volume: to be chosen based on the number of samples and the size of the containers
• Uniformity vs. Gentleness: Forced convection for uniformity, natural convection for gentle crops

For those who also need controlled lighting — for example for plant growth or insect breeding — it is possible to evaluate FDM growth chambers, which combine the functions of the incubator with programmable lighting systems.

The FDM Solution

FDM Environment Makers has been designing and manufacturing laboratory incubators and ovens since 1949, entirely in Italy. Our incubators offer precision PID control, stainless steel tanks, and intuitive control interfaces.

Each incubator can be configured with specific accessories: humidity control, modified atmosphere (CO₂, N₂), lighting systems. For specific needs, we also create custom solutions.

Discover FDM Laboratory Incubators and Ovens or contact us for technical advice.

Reference Standards

• IEC 60068-2-2 — Environmental testing, Test B: Dry heat, reference for steady-state dry heat applicable to the thermal qualification of incubators.
• ISO 11137 — Sterilization of health care products by radiation, specifies incubation procedures for microbiological validation of bioburden.
• CLSI M07 — Methods for Antimicrobial Susceptibility Testing of Aerobic Bacteria, defines incubation conditions at 35 +/- 2 C for 16-20 h.
• ISO 16140 — Microbiology of the food chain: Validation of analytical methods, specifies standardized incubation conditions.
• EN 12322 — In vitro diagnostic systems: culture media, performance criteria and test methods for incubated media.
• CLSI M26 — Methods for the determination of bactericidal activity of antimicrobial agents.

Authoritative Sources

• CLSI – Clinical and Laboratory Standards Institute. American organization that publishes the M07/M26 protocols and M100 documents on antimicrobial breakpoints.
• ISO TC 34/SC 9 Food microbiology. ISO Committee on Food Microbiology and Method Validation.
• EDQM – European Pharmacopoeia. Defines chapters 2.6.1 and 2.6.12 on sterility testing and microbial counting.

Frequently Asked Questions about the Laboratory Incubator

Difference between standard and CO2 incubator?

Thestandard incubator controls only temperature (typically 5-70°C) and is used for culturing aerobic bacteria, incubating agar plates, and for food and environmental microbiological testing. TheCO2 incubator maintains an enriched atmosphere (3-10% CO2, typically 5%) and high humidity (90-95% RH) for culturing mammalian cells, hybridomas, and primary cultures. CO2 is essential for buffering the pH of the bicarbonate culture medium (Henderson-Hasselbalch system): at 37°C with 5% CO2 and 24 mM bicarbonate, a physiological pH of 7.4 is achieved. CO2 incubators integrate: an IR or TCD sensor for CO2, a humidification system with a sterile water tray, and automatic decontamination (UV, H2O2, 180°C dry-heat) to prevent contamination. The choice depends on the application: for diagnostic microbiology CLSI M07 standard is sufficient, for cell culture ATCC or GMP cell therapy and IQ/OQ/PQ qualified CO2 is mandatory.

Why does clinical microbiology use 35-37 C?

The temperature of 35 +/- 2 C indicated by CLSI M07 represents the optimal compromise for the growth of the main human pathogens, most of which are mesophilic with an optimum of 37 C (body temperature). At 37 C , Enterobacteriaceae, Staphylococcus, and Streptococcus grow rapidly, allowing AST readings to be read after 16-20 hours. Lower temperatures (25-30 C) are used for environmental Pseudomonas, yeasts, and filamentous fungi. Higher temperatures (42-44 C) distinguish Campylobacter jejuni (thermophilic) from other species, or select fecal E. coli in water. The clinical microbiology incubator requires uniformity in the usable volume and temporal stability to guarantee MIC (Minimum Inhibitory Concentration) reproducibility. Redundant control with two independent probes is required for ISO 15189 accreditation of clinical laboratories.

How to manage humidity in incubators?

Humidity is critical for prolonged cell cultures: at 37 C with 90-95% RH , evaporation of the culture medium is limited in 96-well plates (vol. 200 uL, passive evaporation of the tray with sterile water at the bottom of the incubator, simple but with risk of contamination; (2) active humidifier with ultrasound or electrodes, with feedback control; (3) steam injection in advanced models with integrated decontamination. To prevent bacterial and fungal contamination, 0.05 M CuSO4 or quaternary salts are added to the tray, or water with conductivity < 1 uS/cm is used, changed weekly. Continuous monitoring with a capacitive probe is mandatory for stem cell and cell therapy GMP. For CLSI microbiological applications, humidity is not controlled but ventilation must avoid drying out of the plates.

Do you need internal UV decontamination?

UV decontamination (254 nm lamp) reduces surface microbial contamination but has limitations: (1) zero penetration in shadows, under shelves, inside plates; (2) reduced effectiveness beyond 1 meter from the source; (3) lamp degradation 30% in 9000 hours; (4) incompatibility with live cells. UV cycles must be performed in an empty chamber with a typical 30-60 min cycle. More effective alternative methods: dry heat 140-180 C for 2-4 h (also eliminates spores), vaporized H2O2 ( 0.35% peracetic acid by nebulization). For GMP cell therapy the typical protocol includes a 180 C thermal cycle every 3 months with biological validation using Geobacillus stearothermophilus spores (6 log reduction). The frequency of weekly manual cleaning with 70% ethanol remains necessary regardless of the automatic system.