Lab Safety And Skills SESEY 2006 Kelly Lab Group

Research Laboratory Safety Research labs are generally safe, but you need to be aware of the hazards YOU are responsible for the safety of: Yourself (look out for #1!) Other people working in the lab The environment and public health

Basic Personal Protection Closed-toe shoes Lab coat Gloves Eye protection No food or drink (including cosmetics)

Chemical Hazards Some chemicals we use can be dangerous Always wear protective gear when handling chemicals, even “safe” ones like NaCl Solvents, acids, etc. must be handled in the fume hood No “unauthorized experiments” allowed! Never taste, smell or feel any chemicals If you’re not sure, please ask your mentor!

Broken Glass and “Sharps” Never put broken glass, needles, razor blades, etc. directly into the trash can Use designated glass and sharps containers, or a cardboard box to dispose of glass Syringe barrels are considered “sharps”, whether or not a needle is attached

Organic Solvents and Waste Hazardous to you and the environment Be careful when handling solvents – most are toxic and/or carcinogenic Always dispose of solvents in a properly marked solvent waste bottle Do not pour any mixtures containing solvents down the drain!

Biohazardous Material “Biohazards” include bacterial cultures, cancer cells, etc. and equipment that contacts them All biohazards must be placed in the red plastic bags to be autoclaved Culture tubes, shake flasks, etc. go in plastic tubs to be autoclaved before being washed Always wear gloves and eye protection around biohazard materials Demo: How to Safely Remove Gloves

General Safety and Courtesy Clearly label all containers, even if they will only be used once Labels should include the contents, your name and the date prepared Clean up chemical spills (e.g. at the balance) immediately and completely If you suddenly start to feel tired, sick or dizzy, tell your mentor immediately!

Laboratory Skills Fundamentals of good lab practices SESEY 2006

Proper Use of Glassware Select clean, dry glassware of the smallest appropriate volume Do not use cracked or chipped glassware Broken or cracked glass goes in special glass containers, never directly in the garbage can Wash used glassware with 1% lab soap Rinse at least 3x with tap water and 2x with deionized water

Weighing and Measuring Balances (aka scales) Balances are delicate, high-precision instruments – treat them gently Always use weighing boats or papers Be careful not to bump balances or drop things onto the balance stage Clean up any spilled chemicals after using the balance Never return excess chemicals to the container – discard them properly

Measuring Large Volumes Always measure liquid volumes in the smallest available glassware to minimize error Read the volume at the bottom of the curved liquid meniscus Guesstimate only one digit in the final result

Measuring Tiny Volumes (<1mL) Pipettors can be adjusted to accurately deliver volumes from 2 µL up to 5000 µL Disposable tips help prevent contamination and ensure consistent volume delivery Practice makes precise! Gilson & Lardy

Set the volume by turning the knob Do not attempt to adjust the volume past the working range printed on the pipettor!!! Attach a clean tip to the pipettor Aspirate (suck up) the fluid: Depress the plunger to the first “soft” stop Insert the tip just below the liquid surface Slowly release the plunger to fill the tip Never “snap” the plunger while releasing! Proper Use of Pipettors

Proper Use of Pipettors (cont’d) Slowly depress the plunger to the second (hard) stop to expel the contents of the tip A bubble will form at the end of the empty tip as air is expelled Withdraw the tip while the bubble is attached to accurately transfer all of the tip contents Discard the used tip in a beaker Transfer the tip to the target container and slowly expel the fluid: Air bubble

Pipettors: Demonstration 1. To Aspirate (suck up): Set the required volume on the pipettor Depress the plunger to first (soft) stop Insert tip below the surface of the liquid Slowly release plunger to draw up liquid 2. To Expel (dispense): Depress plunger past the 1 st stop to expel liquid Stop when a bubble forms (or tip empties) Withdraw the tip from the liquid or container Slowly release the plunger and discard the tip 1 2 ab

Tips for Accurate Pipetting Aspirate slowly to avoid sucking liquid into the barrel of the pipettor (this is a big no-no!) Use autoclaved tips for bacterial/cell cultures Always “wet your whistle” for better accuracy Aspirate and expel once or twice to coat the tip with liquid Insures equal volume when making multiple aliquots Use the same pipettor when dispensing a range of volumes (e.g. 0, 100, 200, …, 1000µL)

Laboratory Notebooks Your record/memory of your work in the lab Often used to resolve legal/patent disputes Entries should be written in permanent ink Pages should be numbered and permanently affixed in the book Sign and date the bottom of each page or entry

Laboratory Notebooks (cont’d) Note the mass or volume of samples, any changes to procedures, unusual effects or results, any calculations, etc. in the lab book Record experimental results and observations directly in the lab book Okay to paste in graphs, photos and diagrams Messy and complete is better than beautiful and useless!

Examples of Lab Notebooks

Laboratory Notebooks (cont’d) Be sure to write down any observations and conclusions after finishing an experiment Keeping a good lab notebook can be one of the most difficult parts of doing research “If it isn’t in your notebook, it didn’t happen.”

Questions?