biotechnology 3 unit 15 study guides

Key Lab Equipment Overview

• Microscopes enable visualization of small specimens and cellular structures (light microscopes, electron microscopes)
• Centrifuges separate substances based on density by spinning at high speeds
  • Benchtop centrifuges are used for small volume samples
  • High-speed centrifuges can pellet cellular debris and organelles
• Incubators maintain optimal temperature and environmental conditions for cell culture and microbial growth
• Spectrophotometers measure the absorbance of light by a sample to determine concentration (UV-Vis spectrophotometers)
• PCR machines amplify specific DNA sequences through repeated cycles of heating and cooling
• Gel electrophoresis apparatus separates DNA, RNA, or proteins based on size and charge when an electric current is applied
• Biosafety cabinets provide a sterile workspace for handling biohazardous materials using HEPA filters and laminar airflow

Safety Protocols and Precautions

• Always wear appropriate personal protective equipment (PPE) such as lab coats, gloves, and safety glasses
• Familiarize yourself with the location and proper use of safety devices (eye wash stations, fire extinguishers, chemical showers)
• Handle chemicals and biological agents according to their safety data sheets (SDS) and established protocols
  • Use fume hoods when working with volatile or hazardous substances
  • Properly label and store chemicals based on compatibility and reactivity
• Dispose of waste materials in designated containers (biohazard bags, sharps containers)
• Maintain a clean and organized workspace to prevent accidents and contamination
• Report any incidents, spills, or equipment malfunctions to the lab supervisor immediately
• Undergo regular safety training and updates to stay informed about current best practices

Basic Lab Techniques

• Pipetting involves using mechanical or electronic pipettes to accurately measure and transfer liquids
  • Always use a new pipette tip for each sample to avoid cross-contamination
  • Calibrate pipettes regularly to ensure precision and accuracy
• Aseptic technique is essential for maintaining sterility and preventing contamination in cell culture and microbiology
  • Work near a flame or in a biosafety cabinet to create a sterile field
  • Minimize exposure of sterile items to the open air and potential contaminants
• Centrifugation is used to separate components of a mixture based on size and density
  • Balance centrifuge tubes properly to prevent damage to the equipment
  • Select appropriate centrifugation speed and time based on the sample and desired separation
• Spectrophotometry measures the absorbance of light by a sample to determine concentration
  • Create a standard curve using known concentrations to quantify unknown samples
  • Use the appropriate wavelength for the substance being measured (e.g., 260 nm for DNA)
• Gel electrophoresis separates macromolecules based on size and charge
  • Prepare agarose or polyacrylamide gels with the appropriate concentration for the target molecule
  • Load samples with loading dye and run at the proper voltage and duration
• Microscopy allows visualization of small structures and organisms
  • Prepare slides with appropriate stains or mounting media
  • Adjust focus, magnification, and illumination to optimize image quality

Advanced Instrumentation

• Flow cytometers analyze and sort individual cells based on fluorescent labeling and light scattering properties
  • Cells are passed through a laser beam in a single-file stream
  • Detectors measure fluorescence and scatter to characterize cell populations
• High-performance liquid chromatography (HPLC) separates, identifies, and quantifies components in a mixture
  • Samples are passed through a column with a stationary phase and a mobile phase
  • Retention time and peak area are used to identify and quantify analytes
• Mass spectrometers determine the mass-to-charge ratio of ions to identify chemical compounds
  • Samples are ionized and separated based on their mass-to-charge ratio
  • Mass spectra are compared to databases for compound identification
• Next-generation sequencing (NGS) platforms enable high-throughput DNA sequencing
  • DNA is fragmented, amplified, and sequenced in parallel
  • Bioinformatics tools are used to assemble and analyze the resulting data
• Microarray technology allows simultaneous analysis of thousands of genes or proteins
  • Probes are immobilized on a solid surface and hybridize to complementary targets
  • Fluorescent labeling is used to detect and quantify hybridization events
• Automated liquid handling systems streamline complex protocols and increase reproducibility
  • Robotic arms and pipetting heads transfer liquids between containers
  • Software controls the movement and volume of liquid transfers

Sample Preparation and Handling

• Proper sample collection and storage are critical for maintaining sample integrity
  • Use appropriate containers and preservatives for each sample type (e.g., EDTA tubes for blood)
  • Store samples at the appropriate temperature and conditions to prevent degradation
• Cell lysis is the process of breaking open cells to release their contents for analysis
  • Mechanical methods include sonication and bead beating
  • Chemical methods use detergents or enzymes to disrupt cell membranes
• Protein extraction isolates proteins from cells or tissues for further analysis
  • Denaturing conditions (heat, detergents) are used to solubilize proteins
  • Protease inhibitors prevent protein degradation during extraction
• Nucleic acid extraction purifies DNA or RNA from cells or tissues
  • Organic extraction uses phenol-chloroform to separate nucleic acids from proteins and lipids
  • Solid-phase extraction uses silica columns to bind and elute nucleic acids
• Sample quantification determines the concentration of the target molecule in a sample
  • Spectrophotometry measures absorbance at 260 nm for nucleic acids and 280 nm for proteins
  • Fluorometric assays (e.g., Qubit) provide more sensitive and specific quantification
• Sample quality control checks for purity, integrity, and functionality of the prepared sample
  • Gel electrophoresis assesses nucleic acid integrity and contamination
  • SDS-PAGE evaluates protein purity and size
  • Functional assays (e.g., enzymatic activity) confirm protein activity

Data Collection and Analysis

• Raw data must be accurately recorded and organized for proper analysis and interpretation
  • Use lab notebooks or electronic lab information management systems (LIMS) to document experiments
  • Include all relevant information (date, sample IDs, protocol details, instrument settings)
• Data processing converts raw data into a format suitable for analysis
  • Background subtraction removes noise and baseline signals
  • Normalization adjusts for variations in sample input or technical factors
• Statistical analysis helps determine the significance and reliability of experimental results
  • Descriptive statistics (mean, standard deviation) summarize data sets
  • Inferential statistics (t-tests, ANOVA) compare groups and test hypotheses
• Data visualization presents results in a clear and informative manner
  • Graphs and charts (bar graphs, scatter plots) display trends and relationships
  • Heat maps and clustering diagrams reveal patterns in large data sets
• Data interpretation draws conclusions and generates new hypotheses based on the results
  • Consider the biological context and implications of the findings
  • Compare results to previous studies and existing knowledge in the field
• Data sharing and reproducibility are essential for advancing scientific knowledge
  • Deposit data in public repositories (GenBank, GEO) for others to access and analyze
  • Provide detailed methods and protocols to enable replication of experiments

Troubleshooting Common Issues

• Contamination can lead to false-positive results and compromise experiments
  • Identify the source of contamination (reagents, equipment, environment)
  • Replace contaminated items and thoroughly clean and sterilize the workspace
• Low yield or poor quality of extracted molecules can hinder downstream applications
  • Optimize extraction protocols for the specific sample type and target molecule
  • Check the quality and purity of reagents and ensure proper storage conditions
• Inconsistent or irreproducible results can arise from various factors
  • Standardize protocols and ensure all team members follow them consistently
  • Calibrate and maintain equipment regularly to ensure optimal performance
  • Use appropriate controls (positive, negative, internal) to validate results
• Instrument malfunction or failure can delay experiments and damage samples
  • Perform regular maintenance and calibration as recommended by the manufacturer
  • Train all users on proper operation and troubleshooting procedures
  • Have backup plans or alternative methods in case of equipment downtime
• Unexpected or discordant results may indicate underlying issues with the experimental design or assumptions
  • Carefully review the literature and consult with experts in the field
  • Consider alternative hypotheses and design follow-up experiments to test them
  • Validate results using orthogonal methods or independent data sets

Practical Applications in Biotech

• Drug discovery and development rely on various biotech techniques
  • High-throughput screening identifies potential drug candidates
  • In vitro and in vivo models are used to assess safety and efficacy
• Genetic engineering allows the modification of organisms for specific purposes
  • Recombinant DNA technology is used to produce therapeutic proteins (insulin, monoclonal antibodies)
  • CRISPR-Cas9 enables precise genome editing for research and potential therapies
• Biomanufacturing involves the production of biological products on a large scale
  • Fermentation and cell culture are used to produce enzymes, antibiotics, and other biomolecules
  • Downstream processing purifies and formulates the final product
• Diagnostics and biomarkers help detect and monitor diseases
  • PCR and immunoassays are used to identify infectious agents or disease-specific markers
  • Liquid biopsies analyze circulating tumor cells or DNA for cancer monitoring
• Agricultural biotechnology aims to improve crop yield, nutrition, and resistance to stresses
  • Genetic modification introduces desirable traits (herbicide resistance, increased nutrient content)
  • Marker-assisted selection accelerates traditional breeding programs
• Environmental biotechnology develops sustainable solutions for pollution and waste management
  • Bioremediation uses microorganisms to degrade contaminants
  • Biosensors detect and monitor environmental pollutants