Chemical and Radiation Safety

General precautions:

Lab coats must always be worn in lab. Safety goggles must be worn when working with UV light. Gloves must be worn when working with hazardous chemicals. Note that phenol and chloroform may penetrate gloves – contaminated gloves should be removed and disposed of immediately. For all chemicals listed below, avoid inhalation & skin or eye contact. In case of skin or eye contact, rinse with large amounts of water for 15 minutes and notify one of the TAs.

Hazardous Chemicals:

In the summer of 1989, the Canadian Federal government introduced the Workplace Hazardous Materials Information Systems (WHMIS) legislation, which requires information on hazardous materials to be made available to any employees coming into contact with such substances. This information is commonly provided by the supplier on Material Data Safety Sheets (MSDS). Unfortunately, not every hazardous chemical is listed under WHMIS legislation; for those that are listed, MSDS are available in the lab, and may be accessed online at:

http://www.fishersci.ca/msds.nsf

Compounds are classified as to their toxicity, corrosivity, flammability, etc. and information is given on the safe handling and disposal of these compounds. The following tables list a summary of relevant information for the more dangerous chemicals that may be used in the labs for this course.

Hazardous Chemicals

chemical	use of chemical	hazards	handling	disposal
acrylamide	polyacrylamide gel precursor	neurotoxin, irritant, suspected carcinogen	gloves, dust mask (crystals)	polymerized gel may be disposed of in regular garbage
chloroform	nucleic acid purification	toxic, irritant, mutagen, corrosive to some plastics	gloves, fume hood	solvent waste (in fume hood)
ethidium bromide	fluorescent dye; detection of nucleic acids	mutagen, irritant	gloves; light sensitive	designated waste container (for incineration)
formamide	DNA hybridization	irritant, teratogenic	gloves, fume hood	solvent waste (in fume hood)
phenol	nucleic acid purification	toxic, corrosive	gloves, fume hood, store at 4°C	solvent waste (in fume hood)

Radiation Safety

In lab 5, a ³²P-labelled probe will be used to detect histone DNA sequences in a Southern blot and a plaque lift. ³²P is a moderate energy beta particle emitter, so proper safety procedures must be followed. You will not be handling ³²P directly (labelling and hybridization will be demonstrated by TAs). However, if you choose to observe the demonstration, keep the following 3 principles in mind: Time, Distance, and Shielding.

Time refers to minimizing the amount of time you are actually exposed to the radiation. Distance refers to maximizing the distance between you and the source of radiation. Shielding refers to placing an effective shield (e.g. plexiglass) between yourself (and anyone else in the area) and the source of radiation. Exposure levels must be properly monitored, and will be demonstrated in the appropriate lab period. Radioactive waste materials (tubes, gloves, liquids) must be handled separately from other waste and placed in labelled radioactive waste containers.

Centrifugation

Proper use of centrifuges will be demonstrated in the lab. Rotors must be balanced and properly seated in the centrifuge, and centrifugation speed must not exceed the limits of the tubes, rotors or centrifuges used. Failure to do this may result in collapsed tubes, loss of sample, and damage or contamination of equipment. Desktop microfuges will be used for most lab procedures.

For other centrifuges, useful information may be available from manufacturers. Sorvall provides information on G-force for various rotors at various speeds, and Nalgene provides information on maximum G-force particular types of tube can withstand, as well as resistance to autoclaving and organic solvents.