Unit 1

• Hazard


  Something that can cause harm
• Risk


  The likelihood of harm arising from the exposure to a hazard
• Hazards in a lab


  • Toxic or corrosive chemicals
  • Heat or flammable substances
  • Pathogenic organisms
  • Mechanical equipment
• Minimising risks and reducing hazards

  1. Identifying hazards

  2. Creating a risk assessment

  3. Using appropriate handling techniques

  4. Using protective clothing and equipment

  5. Using aseptic techniques
• Risk assessment


  A process to identify hazards, assess risks, and implement control measures
• Risk assessment


  1. Describe activity

  2. Identify hazard

  3. Identify persons affected

  4. Assess risk level before controls

  5. Implement control measures

  6. Assess risk level after controls
• Risk assessment examples


  • Lighting a Bunsen
  • Electrolysis of copper chloride solution
• Linear dilutions


  Dilutions differ by an equal interval
• Log dilutions


  Dilutions differ by a constant proportion
• Standard curve


  A graph of known measurements used to determine unknown values
• Buffer


  A solution where adding acids or alkalis have very small effects on the pH, allowing pH to be kept constant
• Colorimeter


  An instrument that can quantify concentration and turbidity by measuring light absorption or transmission
• Calibration


  Setting a baseline reading for a colorimeter using a blank sample
• Centrifuge


  A device that spins samples at high speeds to separate substances by density
• Pellet


  The dense components that settle to the bottom of a centrifuged sample
• Supernatant


  The less dense components that remain in the liquid above the pellet in a centrifuged sample
• Chromatography


  A technique that separates substances based on their differing solubility in a solvent
• Affinity chromatography


  A form of chromatography that separates proteins based on their affinity for specific molecules bound to a solid matrix
• Affinity chromatography


  1. Loading sample

  2. Separation of target and non-target molecules

  3. Elution of target protein
• Gel electrophoresis


  A process that separates proteins and nucleic acids by size and charge as they move through a gel under an electric current
• Native gels


  Separate proteins by shape, size and charge without denaturing them
• SDS-PAGE


  Separates proteins by size alone by giving them an equal negative charge and denaturing them
• Isoelectric point (IEP)


  The specific pH at which a soluble protein has no net charge and will precipitate out of solution
• Isoelectric focusing


  Proteins migrate through a pH gradient until they reach their IEP and precipitate
• Antigen


  A molecule that can be detected by an antibody
• Antibody


  A protein produced by the immune system that can bind to a specific antigen
• Immunoassay


  A technique that uses antibodies to detect and identify specific proteins
• Reporter


  A chemical label attached to an antibody that produces a detectable signal when the antibody binds to an antigen
• ELISA


  An immunoassay technique that uses enzyme-linked antibodies to detect antigens
• Western blotting


  A technique that uses antibodies to identify specific proteins after they have been separated by gel electrophoresis
• Bright field microscopy


  A common microscopy technique used to observe whole organisms, tissues and cells
• Fluorescence microscopy


  A microscopy technique that uses fluorescent labels to visualize specific molecules or structures within cells or tissues
• Aseptic technique


  Procedures used to reduce contamination and the growth of microorganisms
• Microbial culture


  The growth of microorganisms in a controlled laboratory environment
• Primary cell line


  Cells that can divide a limited number of times in culture
• Tumour cell line


  Cells that can divide an unlimited number of times in culture
• Haemocytometer


  A specialized microscope slide used to estimate the number of cells in a liquid culture
• Vital staining


  A staining technique that only stains living cells
• Henrietta Lacks' cancer cells were taken and cultured without her permission, becoming the HeLa cell line which has been invaluable for medical research
• Henrietta Lacks died in 1951 without knowing the impact her cells would have, and her family was unaware of this until 1975