Incubator – Definition, Principle, Components, Types, Operating Procedure, Use.

What is Laboratory Incubator?

An incubator serves as a temperature-controlled, insulated container that laboratories utilise for cultivating and maintaining various biological cultures. This essential piece of equipment creates optimal conditions necessary for growing microorganisms in artificial environments. Like most sophisticated lab instruments, it maintains precise control over environmental factors such as temp, moisture levels, and CO2 concentrations– creating a contamination-free workspace for cell and tissue cultivation.

These specialised chambers – vital for both unicellular and multicellular organism growth- incorporate data loggers with sensors to monitor temperature calibration. The equipment proves invaluable across diverse fields, including:

• Pharmaceuticals– Essential for drug development and testing procedures that require controlled environments.
• Agriculture & Environmental studies – Creates ideal conditions for studying soil microbes and plant pathogens.
• Food & industrial microbiology– Helps maintain cultures needed for food processing, fermentation, and quality control.
• public health research – Supports the growth of bacterial specimens for diagnostic purposes and research.

The laboratory incubator’s applications extend to bacterial cultivation, tissue culture work, biochemical analyses, and haematological investigations. These controlled environments ensure reliable preservation of biological samples whilst supporting various experimental procedures.

Like most sophisticated equipment, incubators play a crucial role in fundamental research and education. They provide students and researchers the ability to study microorganisms under standardised conditions, making them an indispensable tool for modern scientific endeavours.

The device’s primary function revolves around maintaining stable environmental parameters, making it absolutely essential for any facility conducting microbiological or cell culture work. Its enclosed, insulated design ensures precise control over growing conditions, which proves vital for achieving reproducible experimental results.

Incubator definition 

A laboratory incubator is a heated, insulated device used to grow and maintain cell or microbiological cultures by controlling temperature, humidity, and CO2 levels.

Principle of Incubator / Working of Incubator

The incubator functions based on thermoelectricity principle, where it maintains a steady temp through a thermal gradient. When any conductor experiences a heat gradient, it generates voltage – this phenomenon is called thermoelectric effect. The device heats up to a pre-set temperature of 37°C as electrical power flows through the circuit. To maintain this precise temp, three crucial components must work together efficiently: the temp sensor, controller, and contactor.

When someone switches the system on, electrical current energises the contactor that powers the illumination bulbs – these act as heating elements. A fan circulates the heated air throughout the entire setup, ensuring uniform distribution. The fascinating bit is how the digital temp controller monitors everything. Once the temp reaches 37°C, it sends an electrical signal to the contactor which then de-energises, temporarily switching off the heaters. Like most temperature-controlled systems, it’s quite clever – when the temp drops below the desired level, the contactor automatically re-energises to power up the heating system again.

The compatibility betwixt these components– sensor, controller, and contactor – plays a vital role in maintaining optimal conditions. This sophisticated system ensures precise temperature control, which is absolutely essential for various laboratory and medical applications where consistent environmental conditions are paramount.

Through this thermoelectric mechanism, the incubator maintains steady environmental parameters that are crucial for its various applications – whether it’s for microbial cultures, cell growth, or other temperature-sensitive processes.

Parts/Components of Incubator

• Cabinet– The primary structure consists of a double-walled cuboidal chamber ranging from 20-800L capacity, where stainless steel forms the outer wall whilst aluminium makes up the inner wall.
• Glass wool insulation – Fills the space betwixt walls to prevent heat loss and reduce power consumption, ensuring smooth operation of the device.
• Door structure– Features a insulated design with glass panel allowing observation of specimens without disturbing the environment inside, whilst a handle aids maneuvering.
• Control panel – Located on outer wall, houses switches and indicators to manage incubator parameters and thermostat settings.
• Asbestos door gasket– Creates near-airtight seal between cabinet and door, preventing external air infiltration and maintaining isolated conditions.
• Perforated shelves– Connected to internal wall extensions, these hold culture media plates whilst allowing proper hot air circulation through perforations, some models feature removable shelves for thorough cleaning.
• Thermostat regulation– Controls and maintains preset temperature until manually adjusted, quite vital for consistent conditions.
• L-shaped thermometer– Mounted on outer wall with graduations visible outside whilst mercury bulb protrudes slightly into chamber for accurate readings.
• HEPA filtration system – Modern incubators incorporate these filters to minimise contamination risks from airflow through closed-loop air pump system.
• Humidity & gas control mechanisms– CO2 incubators feature water reservoir beneath chamber for maintaining relative humidity through vaporisation, whilst gas chambers regulate proper CO2 concentrations inside.
• Control mechanisms– The control panel houses various switches and indicators that allow precise management of different parameters like temp and humidity.
• Inner projections – The inside wall contains extensions that support the shelves, quite essential for proper placement of culture media.
• Insulation properties– Glass wool between walls acts as brilliant insulator, reducing energy usage whilst maintaining stable internal environment.
• Door features– Besides insulation, incorporates viewing window allowing specimen monitoring without compromising internal conditions.

Component	Description
Cabinet	Double-walled container (20-800L) with stainless steel outer wall and aluminum inner wall. Glass wool insulation between walls reduces heat loss and electricity consumption. Shelves are supported by inward extensions on the inner wall.
Door	Insulated door with a glass pane for viewing inside without opening. Handle on the exterior for easy maneuvering.
Control Panel	Located on the outer wall, it includes switches and indicators for controlling incubator settings, including the thermostat.
Thermostat	Sets and maintains the desired temperature inside the incubator. Keeps the temperature stable once set.
Perforated Shelves	Shelves with perforations allow hot air circulation. Removable shelves in some models for easy cleaning.
Asbestos Door Gasket	Provides an airtight seal between the door and the cabinet, preventing external air from entering and maintaining a stable internal environment.
L-Shaped Thermometer	Mounted on the outer wall, with one end inside the incubator for temperature monitoring and the other outside for easy reading.
HEPA Filters	Advanced models feature HEPA filters to reduce contamination from airflow. An air pump with filters creates a closed-loop system for cleaner air inside.
Humidity and Gas Controllers	CO2 incubators include a water reservoir for maintaining humidity and gas chambers to regulate CO2 levels.

Types of Incubator in laboratory

There are present 11 types of laboratory incubator such as;

1. Cooled incubator– These contain an internal cooling system that maintains temperatures below ambient conditions, while air circulation fans provide precise temperature regulation through various monitoring sensors.
2. Shaking incubator – It combines agitation and temperature control to create optimal conditions for cell development, particularly useful for bacterial cultures and yeast growth in liquid media.
3. portable incubators– These smaller units enable microbiological testing in remote locations, reducing sample deterioration risks during transport and making them ideal for fieldwork.
4. Benchtop incubator – The most commonly utilized lab equipment that operates from room temperature to 100°C, featuring alarms and a glass door with time and temp display screens.
5. CO2 incubator– Creates conditions similar to human body environment, maintaining 37°C temperature, over 90% humidity and neutral pH for biological cell cultivation.
6. BOD incubator – Also known as low-temp incubators, these maintain temps between 20-25˚C, perfect for growing yeasts, moulds and biological oxygen demand testing.
7. Light incubator– Primarily utilized to simulate natural growth conditions for seeds and plants, whilst also conducting photostability testing of various materials like medicines and cosmetics.
8. Anaerobic incubator – Creates oxygen-free environments essential for cultivating challenging anaerobic organisms whilst preventing their exposure to atmospheric oxygen during handling.
9. Constant temp and humidity incubator– Utilises precise control systems to create varied environmental simulation conditions needed in biotechnology testing and industrial research.
10. Analog incubator – The simplest and most economical option, though less precise and lacks a display board to show actual chamber temperature.
11. Digital incubator– More expensive but user-friendly equipment offering superior accuracy and featuring a display board that shows real-time chamber temperature readings.

Operating Procedure of an incubator

Operating an incubator involves a straightforward procedure to ensure optimal conditions for biological experiments:

1. Power source– Make certain that your incubator connects securely to its power outlet before proceeding with any operations.
2. Main power switch – Simply turn it on to begin the initialisation process of your machine.
3. Red power knob– Rotate this control from the 0 position to 1 to activate the system properly.
4. Cooling mechanism – Turn the cooling dial from position 0 to 1 for proper temperature regulation.
5. Temperature calibration– To achieve 22°C, first set lower temp to 21°C using “SET POINT -1” whilst adjusting SET and RST screws with a screwdriver.
6. Upper limit setting – Press “SET POINT -2” to establish 23°C as the upper threshold, simultaneously modifying SET/RST screws accordingly.
7. Temperature ranges —Similarly, one can configure temps of 37°, 44°, 55°C by setting lower limits at 36°, 43°, 54°C and upper limits at 38°, 45°, 56°C respectively.
8. Temperature monitoring – maintain proper records of temps twice daily, morning and evening, with acceptable variation of 2°C from target.
9. Pre-operation check– ensure removal of previous items from incubator chamber, unless multiple organisms requiring identical parameters are being cultured simultaneously.
10. Door operation – Close firmly before switching on and allow proper heating to desired temperature, verified via thermometer.
11. Parameter configuration– Set specific CO2 concentrations and humidity levels if required for particular organism growth.
12. Culture placement – Position petri dishes upside down on perforated shelves to prevent condensation from interfering with colony isolation.
13. Extended incubation– For multi-day cultures, seal plates with adhesive tape or place in plastic containers before final door locking and timing.

Application of Incubator

In laboratories incubator is used for different purpose such as;

• Microorganism cultivation– Incubators provide optimal conditions for growing various microbial and cell cultures in laboratory settings.
• Culture maintenance – These instruments maintain organisms at desired temps for extended periods, whilst ensuring their viability for future utilisation.
• Growth enhancement— Some specialised incubators accelerate the development of slow-growing organisms that typically exhibit prolonged growth cycles in natural environments.
• Biochemical studies– Specific types are utilised for microbial colony reproduction and BOD determination, particularly in wastewater monitoring processes.
• Zoological applications – These are employed for insect breeding and egg hatching processes in zoological studies, providing controlled environmental parameters.
• Sample preservation– incubators offer precise environmental control for storing samples before lab processing, ensuring specimen integrity.
• Food analysis – Laboratory incubators play a vital role in various analytical processes, including food testing, biochemical research and haematological investigations.
• Pharmaceutical research– These instruments support diverse pharmaceutical studies by maintaining specific temperature and humidity conditions.
• Crystal development – incubators facilitate the growth of various crystals, including protein crystals, under controlled environmental parameters.
• Tissue culture– These provide optimal conditions for cell and tissue culture development, maintaining required temp and CO2 levels.
• Environmental monitoring – Used extensively for reproducing bacteria, fungi, and yeast colonies to determine biochemical oxygen demand in wastewater analysis.

Advantages of Incubator

Advantages of laboratory incubators include:

• Energy efficient– Incubators consume minimal power whilst operating, which helps to reduce operational costs and increase overall savings in laboratory settings.
• Parameter customisation – These devices allow modification of different environmental conditions according to the specific requirements of various cell culture types.
• Environmental stability– incubators create perfect conditions that support the development and maintenance of cultures and microorganisms through a combination of natural and forced convection methods.

Limitations of Incubator

Limitations of laboratory incubators include:

• Door management– Extended periods of keeping the incubator door open must be avoided as it significantly raises contamination risks for stored specimens.
• Parameter limitations – These instruments can solely maintain specific environmental conditions like temp, humidity, pH and CO2 concentration at one time, which means different cultures requiring varied parameters need separate incubation cycles.
• Cost implications– The equipment requires substantial financial investment whilst needing skilled personnel for proper operation and maintenance procedures.

Precautions

• Sterile water placement– Pour sterile water beneath incubator shelves during extended operations to prevent culture media from becoming dry and maintain proper moisture levels.
• Parameter monitoring – It’s crucial that all necessary growth parameters are achieved before placing culture plates inside cabinet, ensuring optimal conditions for organism development.
• Plate positioning– Culture plates must be positioned upside-down, with lid at bottom, which helps prevent water condensation onto media surface.
• Regular cleaning – The incubator’s interior requires frequent cleansing to stop organisms from settling on shelves or collecting in corners of the equipment.
• Temperature stability– One should avoid frequent door opening, as these temp fluctuations can significantly affect bacterial growth and development inside cabinet.
• Microbial sensitivity – Since microbes are quite susceptible to temperature changes, repeated opening of cabinet door must be avoided to maintain stable environmental conditions.
• Growth parameters– Before placing culture plates in cabinet, ensure all required parameters for organism growth have been properly established and stabilised.
• Condensation prevention – Position plates upside down, placing lid at bottom to stop water from condensing onto growth media.
• Interior maintenance– Regular cleaning of incubator’s inside prevents unwanted organism settlement on surfaces and corners.
• Water placement – whilst running incubator for long periods, remember to place sterile water under shelves to maintain media moisture.

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