Laboratory Techniques Quiz

Laboratory Techniques

• Measuring and Weighing: Graduated cylinders measure liquids precisely; balances weigh substances (calibration is crucial); pipettes (manual and micropipettes) accurately measure small liquid volumes.

Titration

• Used to determine unknown solution concentrations by adding a known-concentration solution (titrant) until a reaction endpoint occurs (often indicated by a color change, using an indicator).

Filtration

• Separates solids from liquids or gases using gravity, vacuum, or membrane filtration techniques.

Distillation

• Separates liquids based on boiling point differences; techniques include simple (for vastly different boiling points) and fractional (for similar boiling points) distillations.

Centrifugation

• Separates mixture components by density using centrifugal force; common in biology, chemistry labs separating cells, proteins, or precipitates from liquids.

Chromatography

• Separates mixtures into individual components using various techniques:
  • Paper chromatography uses a solvent to move a sample.
  • Thin-layer chromatography (TLC) uses a thin layer of adsorbent (e.g., silica gel).
  • Gas chromatography (GC) and high-performance liquid chromatography (HPLC) separate and analyze volatile and non-volatile compounds, respectively.

Spectroscopy

• Measures absorption, emission, or scattering of light (or other electromagnetic radiation). Types include:
  • UV-Vis spectroscopy identifies and quantifies light-absorbing substances.
  • Infrared (IR) spectroscopy identifies functional groups in organic compounds.
  • Nuclear magnetic resonance (NMR) spectroscopy analyzes molecular structure.
  • Mass spectrometry (MS) identifies compounds based on their mass.

Electrophoresis

• Separates charged molecules (proteins, nucleic acids) in a gel by applying an electric field; identifies sample composition.

Incubation and Growth

• Promotes microorganism or cell growth in specific temperature and conditions (e.g., agar plates, growth media) in the biological and microbiological fields.

Microtomy

• Slices thin specimens (tissues) for microscopic examination using a microtome.

Electrochemical Analysis

• Includes potentiometry (measuring voltage) and coulometry (measuring charge) to analyze solution ions or electrode reactions.

pH Measurement

• Uses pH meters (numerical readings) or pH indicators (color changes) to measure solution acidity.

Microscopy

• Light microscopy observes small organisms or thin materials. Electron microscopy uses electron beams for high magnification, observing ultrastructural details.

Heating and Cooling

• Involves controlled heating (Bunsen burners, hot plates), cooling (ice baths, cryogenic conditions) for reactions, purification, or experimental control.

Buret and Pipette Technique

• Precise liquid handling for measurements and transfers, crucial for titrations.

Lysis and Extraction

• Cell lysis breaks down cell membranes to release cellular content. Solvent extraction uses solvents to isolate compounds.

Serial Dilutions

• Dilutes a substance step-by-step; critical for determining, e.g., bacterial concentration or preparing known concentrations in chemistry.

Bacterial Staining (Microbiology)

• Staining (e.g., Gram staining) identifies bacterial species or structures based on cell wall properties.

Vortexing

• Rapidly mixes liquids (test tubes) for proper sample homogenization.

Vacuum Evaporation

• Removes solvents under reduced pressure to prepare/ purify compounds.

Gel Electrophoresis

• Separates macromolecules (DNA, RNA, proteins) based on size and charge using a gel and electric field.

Solid-Phase Synthesis

• Synthesizes biomolecules (peptides, nucleotides) by adding reagents step-by-step, anchored to a solid support.