Lab Safety Guide for Biochemistry Practical PDF

Introduction of Practical Biochemistry & Safety General Safety Rules: 1. wear your lab coat. 2. Use goggles & gloves if necessary as directed by your instructor. 3. Behave in a respectable and responsible way all over the lab. 4. Do not touch anything from the lab equipment. 5. Assume all...

Introduction of Practical Biochemistry & Safety General Safety Rules: 1. wear your lab coat. 2. Use goggles & gloves if necessary as directed by your instructor. 3. Behave in a respectable and responsible way all over the lab. 4. Do not touch anything from the lab equipment. 5. Assume all chemicals in the lab are dangerous. 6. Do not taste any solution or chemical. 7. Do not pipette any solution by mouth. 8. Do not carry reagents around the lab. 9. No food or drink is allowed in the lab. 10. Know the location of the fire extinguisher, fire blanket, eyewash station, and first aid kit. 11. Wash your hands thoroughly before leaving the lab.  Glassware Safety 1.Chipped or cracked glassware should not be used. 2.Broken glassware should not be disposed of in a classroom trashcan. 3.When pouring liquids into glassware, make sure the container you are pouring into is resting on a table at least a hands breadth from the edge. Chemical Safety: 1. Wear protective goggles and a lab apron 2. Never mix chemicals together unless you are told to do so 3. Never taste any chemicals 4.Do not put your nose over the container and inhale the fumes. 5. Never pour water into a concentrated acid. Acid should be poured slowly into water. 6. Wash your hands after handling hazardous chemicals.  Electrical Safety 1.Lay electrical cords where no one can trip on them or get caught in them. 2. Be sure your hands and your lab area are dry before using electrical equipment. 3. Never poke anything into electrical outlets. 4. Unplug cords by pulling the plug and not the cord. 5. Unplug all electrical equipment at the end of the lab period. Heating Safety Close your white coat. Never look into the container while heating it. Never point the end of a test tube being heated at yourself or others. Never heat in a closed container. Requirments Surgical mask White coat Your card Test tubes Rack Test tube holder Dropper Towel & Brush Lab Safety Symbols Harmful Irritant Toxic Corrosive Highly inflammable Oxidising Biohazards Enviromental Hazard Radioactive Explosion Solutions  A solution: is a homogeneous mixture composed of two or more substances. In such a mixture, a solute is dissolved in another substance, known as a solvent. Solute: the substance which dissolves in a solution. Solvent: The substance which dissolves another to form a solution. Saturation: is the point at which a solution of a substance can dissolves no more of that substance and additional amounts of it will appear as a precipitate.  Types of solutions: Percentage solution: is the solution expressed in the unit %. It may be (a) percentage by weight-w/v or (b) percentage by volume-v/v. Molar solution: is an aqueous solution that contains 1 mole (gram-molecular weight) of solute in 1 liter of the solution. Molarity is the number of moles of solute per liter of solution. Normal solution: a solution in which each liter contains 1 equivalent weight of the dissolved substance; designated 1 N.  Normality (N) is a way to quantify solution concentration. It uses the gram-equivalent weight of a solute in its expression of solute amount in a liter (L) of solution. A 1N solution contains 1 gram- equivalent weight of solute per liter of solution. Expressing gram-equivalent weight includes the consideration of the solute's valence. The valence reflects the combining power of an element often as measured by the number of hydrogen atoms it can displace or combine with. A 1.0 gram-equivalent weight is the amount of a substance that will combine with or displace 1 atom of hydrogen. - Normality= the gram molecular weight(GMW) / valence Example: The normality of a 1.0 liter NaCl solution that contains 1.0 gram-equivalent weight will be the GMW of NaCl divided by the valence of NaCl: (atomic weight of Na = 22.99; atomic weight of Cl = 35.45) GMW of NaCl = 22.99 + 35.45 = 58.44 g N = GMW/valence (the valence for NaCl is 1.0) 58.44 g/1.0 = 58.44 g = 1.0 gram-equivalent weight of NaCl = 1N solution of NaCl The normality of a 1.0 liter solution of H2SO4 containing 1.0 gram-equivalent weight will be the molecular weight of H2SO4 divided by the valence of H2SO4: (atomic weight of H = 1; atomic weight of S = 32.06; atomic weight of O = 16) GMW of H2SO4 = 1(2) + 32.06 + 16(4) = 98 g N = GMW/valence (the valence for H2SO4 is 2.0, as there are 2.0 H ions that could be displaced) 98 g /2 = 49 g = 1.0 gram-equivalent weight of H2SO4 = 1N solution of H2SO4 To simply calculate the amount or weight of a substance needed for a desired normal solution, the following formula may be used: Weight in grams = desired normality x volume needed in liters x GMW/valence (W = N x V x GMW/valence) Example: 500 mL of a 0.1N solution of NaOH is needed for a procedure. Calculate the amount of solute (NaOH) needed to prepare the solution. (atomic weights: Na = 22.99; O = 16; H = 1) Valence = 1 (W = N x V x GMW/valence) X g= 0.1N x (0.5 L) x GMW 39.99 / 1.0 X = 0.1 x 0.5 x 39.99/1.0 X = 1.99 1.99 g of NaOH must be diluted to 500 mL to prepare a 0.1N solution.  Normal Saline Solution Normal Saline Solution (NSS) can be used in a number of laboratory methods as for dilutions of some solutions, for stool exams, physiologic exams, tests and much more. NSS is also called 0.85 % sodium chloride solution.  Essential stages in planning an ordinary Saline Solution : 1. Weight 0.85 grams of sodium chloride. 2. After weighing, pipet 50 ml of sterilized water in to a flask. 3. Carefully transfer the powder using a spatula towards the volumetric flask 4. Dissolve the powder by mixing lightly having a stirring rod. 5. Add sterilized water towards the volumetric flask as much as the 100 ml mark. 6. Stir again until all of the powder continues to be dissolved. 7. Transfer to some clean, dry and sterile storage bottle and label correctly. 8. Should you prefer a bigger volume, all you need to do would be to solve for that weight in grams of sodium chloride needed through ratio and proportion. Example: You'll need 1.5 liters of 0.85 percent sodium chloride solution (NSS): Since: 0.85 grams of sodium chloride would be to 100 mL water, through ratio and proportion, you develop this equation : =0.85 X 1,500 mL / 100W = 12.75 grams diluted to some total amount of 1,500 mL (1.5 L) According to this computation, you have 12.75 grams sodium chloride to become considered and dissolved right into a total amount of 1,500 mL (1.5 L) of sterilized water to provide you with 0.85percent sodium chloride or NSS