Safety Guidelines for Biochemical Laboratories

Safety Guidelines for Biochemical Laboratories

Safety Guidelines for Biochemical Laboratories No eating or drinking is allowed in any chemical laboratory. ESSENTIAL PERSONAL PROTECTIVE EQUIPMENT FO...

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Safety Guidelines for Biochemical Laboratories No eating or drinking is allowed in any chemical laboratory. ESSENTIAL PERSONAL PROTECTIVE EQUIPMENT FOR ALL PROCEDURES IN A LABORATORY Eye Protection Everyone in the laboratory should be wearing eye protection whenever any work with chemicals is being done. For most of the procedures described in this book, plastic safety glasses are sufficient. Some procedures involve possible splashing of large volumes of hazardous liquids such as a mixture of isopropanol and dry ice, high-speed rotary devices, or high-frequency vibrational devices. For such procedures, safety goggles should be worn. Laboratory Coat Everyone in the laboratory should be wearing a laboratory coat whenever any work with chemicals is being done. The sleeves should extend to the wrists. Gloves Most of the procedures in this book may be performed safely without gloves. Wear gloves, however, when handling any hazardous chemicals (refer to Table s.1). The chemicals listed in this table are identified as hazardous within the appropriate exercises. If you are allergic to latex, wear nitrile or other hypoallergenic gloves.

TABLE s.1  The Most Hazardous Chemicals to be Used in the Exercises in this Book Chemical

Procedure(s)

Hazarda

Dithiothreitol

Assay for LuxG-his6 activity

Neurotoxin, respiratory tract irritant

NiSO4

Purification of LuxG-his6

Carcinogen, teratogen

Phenylmethanesulfonyl fluoride

Lysis of spinach and bacteria

Toxic to nerves, heart, blood, eyes

Acrylamide

Gel electrophoresis

Neurotoxin, carcinogen, teratogen

N,N,N´,N´-tetramethyl-ethylenediamine Polymerization of acrylamide

Burns skin and eyes, flammable

Ammonium persulfate

Polymerization of acrylamide

Burns skin and eyes

2-sulfanylethanol (2-mercaptoethanol)

Denaturation of protein

Skin and eye irritant, respiratory tract irritant, mutagen

5,5-diethylbarbituric acid (barbital)

Electrophoresis of the isoenzymes of LDH

Neurotoxin, carcinogen

5-methylphenazinium methyl sulfate

Stain for activity of LDH

Irritant to respiratory tract, eyes and skin

Nitro Blue Tetrazolium

Stain for activity of LDH

Irritant to respiratory tract, eyes and skin

Coomassie Brilliant Blue G-250

Bradford assay, detection of protein in gels Irritant to respiratory tract, eyes and skin

Phosphoric acid

Bradford assay

a 

Burns eyes, skin, and respiratory tract; toxic to liver, blood, and bone marrow

Health hazard information from the Material Safety Data Sheet on the Sigma-Aldrich website: http://www.sigmaaldrich.com.

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SAFETY GUIDELINES FOR BIOCHEMICAL LABORATORIES

Proper Footwear Everyone in the laboratory must wear closed-top shoes that do not have high heels. HEALTH HAZARDS FROM LABORATORY EQUIPMENT For all of the equipment described below, obtain instructions from the instructor or the teaching assistant before using the device. You should be supervised during your first use of the device. Motor-driven Homogenizers Instructions and photos explaining proper use are in the experimental sections. To ensure your safety, be certain the pestle shaft is tightly secured within the chuck of the drive. During homogenization, the glass receptacle should be held near the top because it is more likely to shatter near the bottom than the top. Centrifuges A two-pan balance must be used to bring samples that will be on opposite sides of the rotor to an equal mass before loading. Samples should be in a screw-cap tube or bottle that is designed for the amount of centrifugal force that will be applied (photo in the first exercise on ferredoxin-NADP+ reductase). The tubes or bottles will be open while balancing (to allow addition of more solution) but the caps should be on the balance trays. If rotor adaptors are to be used, they should also be on the trays. In most cases, the rotor is only secured to the centrifuge spindle if its cap has been screwed on tightly. After starting the centrifugation, stay near the centrifuge until it reaches the desired rotational speed. If severe vibration of the machine occurs, stop the centrifugation immediately! Devices for Electrophoresis Instructions and photos on the proper use of these devices are provided in the experimental sections. Relatively high voltages of direct current are used, and the buffers are excellent conductors. The main concern for safety is that the operator might dip a finger into a buffer tank after the voltage has been applied, and if there is a conduction path through the operator, a severe electric shock might be experienced. The devices described in this manual have safety interlocks that are designed so that the electrical circuit is not completed until the lid is covering the buffer tanks. Most electrophoretic apparatuses have a similar design. In spite of this safety feature, have the power supply turned off when the lid is not on and the buffer tanks are not covered. Emitters of High-frequency Sound The frequency emitted by a sonifier can damage the human ear. Instructions and photos regarding safe use of this device are provided in the first exercise for LuxG. In particular, the operator should wear ear muffs and eye protection. Gas Burners and Hot Plates In preparing a boiling water bath for the denaturation of protein, boiling chips should be used and an electrical hot plate is preferred to a gas burner. When you are finished with the experiment, the hot plate should be turned off and unplugged. The valve at the counter top for any gas burner should be closed immediately after it has been used.

Hazardous Chemicals

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HAZARDOUS CHEMICALS Definitions Department of Environmental Health and Safety

At most universities, this department establishes safety regulations for the use of all campus laboratories (it may have a different name in some cases). The staff of the department of environmental health and safety also enforce policies and provide services such as the certification of fume hoods, the disposal of hazardous waste, the maintenance of safety showers and stations for washing eyes, and the response to emergencies. Some colleges may not have a department of environmental health and safety, but all schools with chemistry laboratories will have a safety officer to handle these issues. Material Safety Data Sheet

The Material Safety Data Sheet (MSDS) provides information on volatility, flammability, toxicity, corrosiveness, and other properties of a hazardous chemical. Carcinogen

A chemical known to induce mutations that may lead to cancer in the individual that has been exposed. Concerns for Pregnant Women Teratogen

A chemical known to induce mutations that may lead to developmental abnormalities in a fetus. Fetotoxin

A chemical that may be toxic to a fetus. Information Sources The Web sites for chemical supply firms usually provide links to the Material Safety Data Sheets for their products. It is also helpful, however, to have access to open-source databases of Material Safety Data Sheets. Sigma-Aldrich Chemicals: http://www.sigmaaldrich.com (no subscription necessary). Where to Find a Material Safety Data Sheet on the Internet (by Interactive Learning Paradigms, Inc.): http://www.ilpi.com/msds/index.html. Chemwatch ChemFFX (from Global Chemical Data Inc.): mailto:[email protected] http://www.chemwatchna.com/OurServices/MSDSManagement.aspx. ChemQuik (from Actio Corp., Portsmouth, NH): mailto:[email protected] http://www.actio.net/default/index.cfm/products/chemquik/.

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SAFETY GUIDELINES FOR BIOCHEMICAL LABORATORIES

Minimization of Exposure Volatile Chemicals

The laboratory should have a chemical fume hood that is certified at appropriate intervals by the staff of the department of environmental health and safety. Stock bottles and waste containers for volatile chemicals should be kept in the hood. Corrosive, Toxic or Carcinogenic Chemicals

Wear disposable gloves when handling. If any are spilled on skin, rinse immediately with water. HAZARDOUS WASTE DISPOSAL Follow the instructions provided by the instructor or the teaching assistant for disposal procedures for sharp waste, hazardous chemicals, and biohazards (for example, material contaminated with recombinant bacteria). EMERGENCY RESPONSE The instructions below for providing immediate assistance are for the instructor, the teaching assistant, or the student. If it appears necessary, a call for professional emergency medical help should be made. Before the first day of class, learn the campus policy covering procedures for such calls. On some campuses, the policy may be to call 9-1-1 directly from the lab. At other schools you may be required to call the department of environmental health and safety or campus health services so that they can call 9-1-1 and direct the responders to the desired location. Contact of Skin or Eyes with Hazardous Chemicals The laboratory should have emergency showers and eye-wash stations at the sinks. The instructor, teaching assistants, and students should be aware of their location and how to use them. If necessary, call the National Capital Poison Center, 800-822-1222, http://www.poison.org. Injuries The laboratory should have a first-aid kit. Everyone working in the laboratory should know where it is located. If an instructor, teaching assistant, or student believes he or she has the necessary understanding to treat a minor injury, they should assist in the treatment. Sudden Illness such as Fainting or Nausea Move the affected individual out of the laboratory and away from chemical vapors or other hazards. If the recovery is not rapid and the individual’s condition seems serious, call for professional medical help as described above. Chemical Spills There should be a spill kit in the lab. The instructor or the teaching assistants will instruct you in how it is used. It should contain: 1. Sodium carbonate or sodium bicarbonate for acid spills. 2. Citric acid or sodium bisulfate for alkali spills. 3. Inert adsorbents such as vermiculite, clay, or sand for hazardous liquids.

Emergency Response

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Fires The instructor, the teaching assistants, and the students should know the location of the fire extinguishers and be prepared to use them. Learn the evacuation plan on the first day of class. Earthquakes If you are in a region prone to earthquakes, learn the recommended response on the first day of class.