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Gel Room, Dark Room, Radioisotope Room And Cold Room Safety

Gel Room Safety

Electrophoresis is a commonly used laboratory technique which uses electrical energy to separate molecules such as proteins or nucleic acids by their size, structure, and electrical charge. Electrophoresis work poses potential electricalchemical and thermal safety hazards.

Electrophoresis equipment can pose significant electrical hazards in the laboratory. Typical electrophoresis units operating at 100 Volts can provide a lethal shock of 25 milliamps. Take the following precautions when working with electrophoresis equipment:

Power Supplies:

  • Ensure all switches and indicators are in proper working condition and that power cords and leads are undamaged and properly insulated.
  • Label equipment with the warning: “Danger Electrical Hazard.”
  • Connect equipment to outlets with ground fault circuit interrupters (GFCIs).
  • Use power supplies with safety features that detect issues with the electrical circuit (e.g.,

no-load, overload, sudden load changes, short circuits, etc.).

 Connecting Leads:

  • Turn off main power supply before connecting or disconnecting electrical leads.
  • With dry gloved hands, connect one lead at a time using one hand only.
  • Be sure that leads/banana plugs are fully seated.

Using Equipment:

  • Don’t run equipment unattended.
  • Keep equipment clear of unintentional grounding points and conductors (e.g., sinks or other water sources, metal plates, jewellery, aluminium foil, pipes or other electrical/metal equipment).
  • Gel chamber must have a lid or cover with safety interlocks to prevent accidental contact with energized electrodes or buffer solutions.
  • Gel chamber exterior must be dry with no spilled solutions. Check the chamber for leaks.
  • Switch off all power supplies and unplug the leads before opening the gel chamber lid or reaching inside the gel chamber. Do not rely on safety interlocks.

Users may be exposed to thermal hazards when heating agarose solutions.

Ultraviolet (UV) light boxes and handheld lamps are often used in visualizing ethidium bromide gels and pose potential exposures to UV radiation.

Hazardous chemicals commonly used in conjunction with electrophoresis work include:

  • Ethidium bromide – mutagen, irritant
  • Acrylamide – carcinogen, neurotoxin, irritant
  • Phenol – corrosive, toxic 
  • Chloroform – suspect carcinogen, toxic 

General Work Practice:

  • Read and follow manufacturer’s instructions for electrophoresis equipment.
  • Instructions should include operating procedures written by the manufacturer and laboratory, as well as the associated hazards, the correct personal protective equipment (e.g., lab coats, gloves, and eye protection), and applicable emergency procedures.
  • Use double gloves while working in the gel room, remove the contaminated gloves safely and dispose of before leaving the room.
  • Locations where ethidium bromide is used or stored must be identified with "Mutagenic" marked stickers. Do not remove the hazard out of room.
  • Only trained and qualified users are permitted to operate gel electrophoresis equipment.  Responsible Faculty Member or LS are responsible for ensuring that all users are trained to use the equipment in a safe manner.  Training should include special hazards and safety precautions.
  • Measure, mix, and handle hazardous powdered chemicals or gel prep mixtures with hazardous components (e.g., acrylamide monomer, phenol, ammonium persulfate, and formaldehyde) in the fume hood.
  • Purchase pre-made gels or pre-mixed acrylamide and ethidium bromide solutions instead of making your own.
  • Consider using ethidium bromide substitutes.
  • Exercise caution when using a microwave to melt agarose solutions; don’t use sealed containers, and beware of superheated liquids that may suddenly and unexpectedly boil. Let hot agarose solutions cool to 50-60 °C before adding ethidium bromide or pouring into trays. Wear insulated gloves and point the flask opening away from you.
  • During normal use, small spills may occur and residues may build up on equipment and other laboratory surfaces. A solution of soap and water is recommended for cleaning small spills and removing residues on equipment and laboratory surfaces. For more information see Emergency Procedures.

Ethidium Bromide waste in concentrated or solid form is collected as hazardous waste and should not be flushed down the drain or disposed of in the trash. Gels containing ethidium bromide can be easily de-stained in the laboratory by simply placing the gels in a DI-water bath for 15 minutes and gently agitating or 15 min treatment under UV light. This eliminates the need to collect the gels as a hazardous waste. For information on disposal of other hazardous materials please see Waste Management section. 

Dark Room and Radioisotope Room

Radioactive labelling is conducted in SU and is restricted to Radioisotope room which is interconnected with the Dark room (Room FENS 2078). All potential hazards must be taken into account while conducting experiments in this facility and access is only granted upon corresponding training.

The following describes general guidelines associated with work in the facility, for further information please see Radiation Safetysection.

Dark room

It is of high importance to keep the dark room clean at all times.  All chemicals shall be stored and labelled appropriately. Secondary containers should be placed under all chemicals in storage.


The darkroom is a low light and even no light working environment. Be sure that:

  • There are no obstacles left around that could be tripped over.
  • Check the labels of the chemicals before turning off the main white lights.
  • Make sure equipment that you need is at hand.

Use necessary PPE:

  • Splash proof safety goggles and appropriate gloves are to be used at all times.
  • Dispose of the contaminated gloves prior to leaving the work area. 
  • As in any chemical area, clothing in the darkroom should offer protection from splashes and spills. Clothing should be easily removable in case of accident. 

Dispose of all chemicals through hazardous waste procedure. Take care of any spills immediately (see Emergency Procedures section)

Under no circumstance block the radioisotope room entrance.

Radioisotope room

Radioactive material at SU, is mainly used for biomedical research in the radioisotope room and in the Physics programme. Such research could be interrupted or stopped completely without the use of radioactive materials.

SU is devoted to ensure that the use of radioactive materials is carried out in a safe manner for employees, students, the public and the environment.

In Turkey, the possession and the use of radioactive materials is governed by the Radiation Safety Rules and Regulations administered by the Turkish Atomic Energy Agency (TAEK). SU holds a consolidated license covering the possession use, storage, import and export of radioactive materials, and a waste license covering the disposal of radioactive materials.

General Safety Practices

In the use of radioactive materials for teaching or research, consideration must also be given to other physical, chemical and biological hazards which may arise during the procedure. Care should be taken to ensure that the safety requirements necessary for radioisotope use do not compromise the safety requirements for the use of other hazardous agents

Work Area Safety

  • All radioisotopes must be kept locked. Only authorized people can work with them.
  • Work must be limited to an area in laboratory with minimal traffic.
  • All radioisotope usage areas must be labelled properly with radiation warning labels.
  • Radioactive waste keeping should not be performed without adequate shielding and containment, since the users working in this area may be exposed to radiation.
  • Disposable absorbent materials must be used to cover work area, and in the case of a spillage this area must immediately be evacuated.
  • Radioisotope work areas must be obstacle free. For example, laboratory records and books should be kept away from possible contamination.
  • If there is a possibility of volatilization of the radioactive material, working under fume hood is a necessity. A dry-box or transfer-hood must be used working with dusty radioactive materials. In addition, gloves, safety glasses and, if necessary, face masks or respirators, must be worn.
  • Fume hoods must not be used for storage of materials which may disrupt the air flow.
  • A radiation dosimeter (whole body) must be worn at all times according to specified radioisotope permit. Also wearing an extremity dosimeter (ring badge) in case of a specific radioisotope is a necessity.
  • Within seven days of the usage of radioisotopes, monitoring and contamination control checks must be carried out.
  • Eating, drinking, use of cosmetics or other material in contact with the skin is strictly forbidden in the laboratory. Food containers must not be stored in a radioisotope laboratory or in a refrigerator used to store radioisotopes.
  • Before working with radioactive material, any wound in the skin should be properly protected by a waterproof covering.
  • All equipment used during a radioisotope procedure must be labelled with appropriate radiation warning labels. If possible, this equipment must be kept separate from general laboratory area. If an item is decontaminated, remove the warning labels.
  • Radioactive solutions must be labelled with radiation warning tape including relevant information  such as the activity and its radioisotope. All containers contaminated with radioactive materials must be labelled, covered and stored properly.
  • Designate proper glassware for radioisotope work. Wash them separately with a detergent explicitly designed for radioisotope work. Store these glassware in a separate marked area. Decontamination of these exposed glasswares must be done properly before being returned to general use.
  • Use only one sink for cleaning of contaminated glassware and equipment. Label this sink with proper radiation warning signs.
  • In order to prevent the spread of radioactive spills, cover it with absorbent materials. The spill area must be marked to warn others. In this case, initiate the decontamination of the area as soon as possible.
  • Usually, equipment may be washed with a proper laboratory detergent. Use chelating agent or ultrasonic cleaning if necessary. Unsatisfactorily decontaminated equipment must be stored separately until the radiation has decayed sufficiently or it must be discarded as radioactive waste.
  • To encourage laboratory users to remove contaminated clothing before leaving the laboratory, coat hooks must be installed near the exit door.
  • Before starting maintenance in radioisotope laboratory, locally decontaminate the working area.
  • All users must wash their hands after using radioisotope laboratory.

Cold Room Safety

The intention of cold rooms is to properly store certain agents and to conduct certain tests at a controlled temperature.

The supplied air in cold rooms is intended to prevent the buildup of carbon dioxide generated from users in the room as well as other contaminants that might be released in the room. Nevertheless, this small volume of supplied air creates moisture problems contributing to mold growth, especially when trace contaminants are present on surfaces. 

A number of health and safety problems can occur in cold rooms. These problems range from inhalation exposure of mold, to unsafe use/storage of chemicals resulting in inhalation exposures, and storage of food and drinks in cold rooms resulting in potential ingestion exposures to molds. 

To that extent, these guidelines are recommended to minimize mold growth, recommend correct chemical and biological use and storage, and list some activities that are prohibited. Users can experience inhalation exposures to mold and a buildup of carbon dioxide when they are in cold rooms.


Minimizing Potential Mold Growth

In many cold rooms various molds are available. A cold room contamination with mold can happen quickly if an improper procedure occurs. It results to potential health problems from breathing of the mold spores and contamination of used materials.

The storage of cellulose containing materials leads to mold growth. Also, mold growth can lead to contamination of research substances. Mold growth in cold rooms can be prevented by controlling condensation/moisture and removing materials. The following procedures can be considered:

  • Clean up spilled liquids (e.g., buffers, media). Mold growth can initiate on an organic medium.
  • Inform water leaks to LS/LSS.
  • Keep door shut to prevent condensation. Left open doors can increase the relative humidity in the working area which supports mold growth.
  • Damaged door gaskets can provide a cold surface resulting in condensation problems. Be aware of condensation on other sections as well. Sometimes condensation is an sign of decontamination. Inform LS for an assessment of the problem.
  • Eliminate all wood. Wood can absorb moisture and, since it is composed of cellulose, it is a perfect ground for mold growth. Wood shelves must be replaced with stainless steel shelves that allow air flow throughout the storage area.
  • Eliminate all products which contain cellulose, such as cardboard and paper. These surfaces act like wood and promote mold growth. If paper products are required, store them in an enclosed plastic container between uses. If visible mold found on a paper product, throw away the item immediately.
  • Keep surfaces clean. Do not use bleach on metal surfaces, because bleach on metal surfaces can result in pitting. Wet clean-up activities are recommended. For example, dusting, sweeping or brushing will spread mold into the air and can cause breathing exposures and spread potential contamination.
  • If you need minor cleaning, use following wet clean up method. For example,  dampen cloth with a non-ammoniated soap or detergent (do not combine ammonia and bleach; produced fumes are highly toxic).
  • If mold reappears soon after cleaning, use any hospital approved disinfectant, drying surfaces after cleaning to ensure moisture has been removed.
  • Users will be held responsible for cleaning mold growth if LS/LSS inspections note improper actions that could contribute to mold growth.

Proper Chemical Use and Storage

Cold rooms can recirculate the air contained within. Vapor of chemicals in the air can accumulate and pose a breathing exposure or an explosion hazard to laboratory users. Therefore:

  • Flammable solvents can spread sufficient vapors to form an explosive atmosphere. Fans and electrical laboratory equipment in these rooms are potential ignition sources. Do not store large quantities (>1 liter) of flammable solvents in cold rooms. A standard refrigerator must never be used for the storage of flammable materials. Instead, use flammable storage refrigerators.
  • Cold rooms have a contained atmosphere, some hazardous chemicals such as chloroform, formaldehyde which are not flammable may vaporize and cause exposures to users. All users should consider the risk when applying experiment procedures and evaluate those procedures where vapors are released in a chemical fume hood. Quantities need to be limited to less than 250 mL (note: chemicals such as chloroform vaporize very quickly. Such chemicals should NOT be placed in squeeze dispenser bottles.
  • In cold rooms, prompt removal of the spilled materials is essential.

Prohibited activities

To provide the safety of all users, the following activities are forbidden in cold rooms:

  • Storage of food and beverage: Storage of any beverages or food is explicitly prohibited.
  • Usage of compressed gas: Gases released from incubators in a cold room can cause a lowering of the oxygen level, resulting in possible asphyxiation. Gases must be used outside of a cold room. In case of a gas usage in a cold room, an oxygen sensor which is equipped with a local alarm, must be installed in the cold room in order to warn other users if a low oxygen level occurs.
  • Never store dry ice in a walk-in cooler. Dry ice can create an oxygen deficient atmosphere when it sublimes and releases gaseous carbon dioxide.
  • A single individual may create problems affecting all users since most cold rooms are shared between multiple groups. If there is a problem, the Responsible Faculty Member or LS, and furthermore all users, must take the appropriate action to resolve the issue.

LS will notify users of cold rooms of improper use issues.