CO2 Incubator

April 24th, 2014 by Acmas No comments »

As it is very well known that incubator maintains optimal temperature, humidity and other conditions such as Carbon dioxide (CO₂) and oxygen content of the atmosphere inside. CO₂incubator controls the CO₂ level to 5% and it works on three building blocks

Carbon dioxide
Temperature
Relative Humidity

CO₂ incubators are usually set to 37°C. This is the optimal working temperature for promoting healthy cell growth. The external indicators of the incubator do often provide a good sense of the internal environment, but it is often useful to keep a good thermometer inside to keep a record of the internal temperature.

The chambers of CO₂ incubators are sometimes incorporated with copper which is used for eliminating the contamination in incubators, as copper breaks down it releases copper oxide which destroy microbes that are present in the chamber.

CO₂ incubator may be

Water-jacketed; envelopes the unit’s chamber and provides superior insulation while eliminating contamination and cold spots.The water-jacket is also surrounded by insulation, which makes the incubator ideal for maintaining precise conditions.

Air-jacketed; an air-jacket CO₂ incubator has a heated inner chamber that is controlled by sophisticated microprocessors. These microprocessors constantly monitor and adjust program settings and allow calibrations of CO₂ and temperature.

For both types of incubators, the microcomputer controls include backup systems that prevent samples from overheating, plus alarms that monitor the out-of-tolerance conditions.

Maintaining the chamber’s environment (CO₂ control)

To maintain the chamber environment for safe and reliable research, CO₂ incubators are equipped with precise automated controls. These controllers are of three types.

Continuous Flow; provides manual control of the air and CO₂ flow rate through the use of precision-bore glass tube flow meters. For this method an accessory air pump is required.
Thermal Conductivity (TC)sensor ; more indirect method of CO₂detection and control since it measures the level of CO₂ by sensing temperature differences as CO₂ is introduced into the chamber.
Infrared (IR); This method uses an infrared sensor to detect a change in CO₂ concentrations as little as 0.1 %. Since the IR sensor is unaffected by changes in temperature and humidity, it is ideal for applications in which the incubator door is frequently opened, and provides nearly perfect culturing conditions for cell growth. The sensor continuously samples chamber atmosphere through a spectrophotometer flow cell, checking wavelength and instantly correcting an out-of-control condition. Also, CO₂recovery is rapid and changes in CO₂ concentration are made within seconds.

Areas of Application

Tissue Culture
Food and dairy processing
Stem cell research
Biochemical, bacteriological and hematological studies
In vitro fertilization
Virological studies

Safety Guidelines

Incubator should be located on a solid work surface that should be away from high traffic areas and extreme temperatures (Constant temperature is easier to maintain if the incubator is not in the direct contact of airflow from air conditioners or heat sources.
Electrical cord of the incubator should be routinely inspected for any damage (Electrical cord should not be used for cord repair).

This thermometer must also be cleaned with 70% alcohol on a regular basis to maintain its integrity.
The internal humidity of the incubator is usually maintained, by a tray of water which is kept topped up on a weekly basis. It is essential to always use sterile distilled water to do this. The tray which holds the water must also be cleaned to prevent the expensive and time-consuming results of contamination by unwanted invaders. The incubator should be cleaned with 70% alcohol between uses and internal removable parts should be autoclaved to achieve full sterilisation.

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Clean room – And Its Types

April 23rd, 2014 by Acmas No comments »

A specially constructed enclosed area, which is environmentally controlled with respect to airborne particulates, temperature, humidity, air pressure, air flow patterns, air motion, vibration, noise, viable (living) organisms, and lighting is defined as CLEAN ROOM.

The purpose of the clean room air-conditioning system is to supply airflow in sufficient volume and cleanliness to support the cleanliness rating of the room. Air is introduced into the clean room in a manner to prevent stagnant areas where particles could accumulate. The air must also be conditioned to meet the clean room temperature and humidity requirements. In addition, enough conditioned makeup air must be introduced to maintain the specified positive pressurization.

On the basis of the method of air flow or ventilation in the clean room, the clean rooms are differentiated into following two types

Laminar air flow clean room
Turbulent air flow clean room

Laminar Air Flow Clean Room; air flow pattern is in one direction, that may either be horizontal or vertical at a uniform speed of between 60 to 90 ft/minutes and throughout the entire space.

Figure no.1; showing the laminar air flow

When there is no obstruction to the airflow, removal of conta clip_image002 mination occurs faster, but when there are obstructions, these obstructions cause the laminar air flow to be turned into turbulent air flow around the obstructions. Then this turbulent area formed got established with higher contamination concentrations. The cleanliness of a laminar air flow clean room is directly proportional to the air velocity.

Turbulent air flow clean room; the general method of ventilation is similar to that found in buildings such as living areas such as offices schools and malls, manufacturing plants etc. but a clean room differs from an ordinary ventilated system through the following points

Figure no.2; showing the turbulent air flow.

Increased air supply; important aspect of particle control. Mainly provided to dilute to an acceptable concentration the contamination produced in the room.
High efficiency filters; filter the air supply and ensures the removal of small particulates.
Room pressurization; provided to ensure that untreated air does not pass from dirtier adjacent areas into the clean room.

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Clean Room – Its Applications and Control of Contaminants

April 23rd, 2014 by Acmas No comments »

Clean rooms are defined as a specially constructed enclosed area, environmentally controlled with respect to airborne particulates, temperature, humidity, air pressure, air flow patterns, air motion, vibration, noise, viable (living) organisms, and lighting.

Particulate control includes:

Particulate and microbial contamination
Particulate concentration and dispersion

Particulate/Contaminants must be continually removed from the air. The level to which these particles need to be removed depends upon the standards required. These standards are

“Federal Standard 209E” defines a clean room as a room in which the concentration of airborne particles is controlled to specified limits.
“British Standard 5295”defines a clean room as a room with control of particulate contamination, constructed and used in such a way as to minimize the introduction, generation and retention of particles inside the room and in which the temperature, humidity, airflow patterns, air motion and pressure are controlled.

Airborne particles occur in nature as dust, pollen, bacteria, miscellaneous living and dead organisms, and sea spray. Industry generates particles from combustion processes, chemical vapors, and friction in manufacturing equipment. People in the workspace generate particles in the form of skin flakes, lint, cosmetics, and respiratory emissions. All these particulates are either to be eliminated, diluted or prevented from settling on to the product surfaces.

The purpose of the clean room air-conditioning system is to supply airflow in sufficient volume and cleanliness to support the cleanliness rating of the room. Air is introduced into the clean room in a manner to prevent stagnant areas where particles could accumulate. The air must also be conditioned to meet the clean room temperature and humidity requirements. In addition, enough conditioned makeup air must be introduced to maintain the specified positive pressurization.
HEPA filters are a critical component in clean rooms. Clean room environments require highly filtered air that is frequently changed and delivered at precise conditions. Air-Handling units for clean room application require specific custom units that accommodate laminar air flow, HEPA and ULPA filtration, and sealed-insulation construction.

Applications of Clean Rooms
Clean rooms are typically used in manufacturing, packaging and research facilities associated with the following industries

Semiconductor ; this industry drives the state of the art clean room design and this industry accounts for a significant number of all operating clean rooms.
Pharmaceutical ; clean rooms control living particles that would produce undesirable bacterial growth in the preparation of biological, pharmaceutical and other medical products as well as in genetic engineering research.
Aerospace; the manufacturing and assembling of aerospace electronics, missiles and satellites were the first application of clean rooms. Large volume clean room spaces with extreme cleanliness are involved.
Miscellaneous applications; other uses include advanced materials research, laser and optic industries, microelectronic facility, paint room and in some aseptic foods production. Also in some high infection risk areas of hospitals.

Control of contaminants

Control is primarily through airflow design. Construction finishes; personnel and garments; materials and equipments are sources of particulate contaminations that must be controlled. Important control precautions include:

Walls, floors, ceiling tiles, lighting fixtures, doors and windows are construction materials that must be carefully selected to meet clean room standards.
People must wear garments to minimize the release of particles into the space. The type of garments depends on the level of cleanliness required by a process. Smocks, coveralls, gloves and head and shoe cover are clothing accessories commonly used in clean spaces.
Materials and equipments must be cleaned before entering the clean room.
Room entrances such as sir locks and pass through are used to maintain pressure differentials and reduce contaminants.

Air shower is used to remove contaminants from personnel before entering the clean spaces.