Laboratory Equipment

Glassware A general term for laboratory equipment that is made of glass. Graduated cylinders Beakers Flasks Pipettes Thermometers Microscope slides Petri dishes Watch glasses

Beakers, flasks and graduated cylinders are containers that hold liquids. These containers can be made of glass or plastic. Generally, you should choose a container that is only slightly larger than the amount of liquid you need. REMEMBER… The precision of measurements increases as the measurements become more detailed.

Beakers – are cylinders with a spout and a flat bottom. Spout makes them useful for pouring liquids. Flask – has a narrow opening at its top and a wider base. Can be sealed by placing a stopper in the opening. Helps prevent liquids from splashing or giving off noxious fumes. Graduated cylinder – “graduated” or marked with a scale for measurement. Used to accurately measure liquid volume. Meniscus – the curve of liquid at its surface when using a graduated cylinder e/labdocs/catofp/measurea/volume/gradcyl.htm e/labdocs/catofp/measurea/volume/gradcyl.htm

Test Tube – narrow glass cylinder that is open at one end. Can use a stopper to seal the opening. Used to hold small amount of liquids. Used to mix, measure, or heat liquids. Pipette – tube that is used to move or transport a measured volume of liquid. Dropper/Eyedropper-simplest pipette Petri Dish – used for growing bacteria on a solid growth medium that contains nutrients. Microscope Slide – piece of glass that is used to hold a specimen that will be observed using a compound microscope. Watch Glass – a holding container

Balances Mass is the amount of matter in an object. Balances measure an object’s mass. Double-pan Balance – has two pans that are used to compare the mass of two objects. Triple-beam balance – determines the exact mass of an object using the positions of the riders on the scales when the balance pointer aligns with the zero mark. Electronic Balance – determines mass of an object electronically.

Time Measuring Equipment Stopwatch – used to determine accurate time. Used for measuring small increments of time, such as seconds or fractions of a second.

Optical Instruments Magnifying Glass Microscopes – a device that enables its user to see enlarged images of small objects  Light Microscope  Compound Microscope  Electron Microscope Transmission Electron Microscope (TEM) Scanning Electron Microscope (SEM) Scanning-Tunneling Electron Microscope (STM)

Magnifying Glass Actually a simple light microscope. Has only one lens Magnifies objects only a small amount. Used to view macroscopic objects (objects large enough to be seen with unaided eye)

Compound Microscopes Uses two or more lenses to form an enlarged and focused image of an object. Allows one to view objects that cannot be seen with the unaided eye Has greater magnification capability than a simple microscope. Magnification – multiply the power of the ocular by the power of the objective ocular – 10X objective – 40X 10x40 = 400 is the number of times an object is magnified.

Electron Microscopes Create images using streams of electrons Will see an image generated on a screen Can magnify up to 500,000 times. Can see parts of the cell to the position of atoms. LIVE ORGANISMS CANNOT BE VIEWED IN AN ELECTRON MICROSCOPE! This is because the specimen must be viewed in a vacuum. Three Types  Transmission Electron Microscope (TEM)  Scanning Electron Microscope (SEM)  Scanning – Tunneling Electron Microscope (STM)

Transmission Electron Microscope (TEM) Used to view the interior of an object Transmits electron beams through a thin slice of specimen to produce an image.

Scanning Electron Microscope (SEM) Uses a specimen most often coated in gold atoms Electron beam scans over the surface of the object, and creates an image Can produce three-dimensional images

Scanning-Tunneling Electron Microscope (STM) Can display objects as small as individual atoms Electron current will give a computer generated image of the specimen

Other Laboratory Tools Ruler – Measures length or distance Thermometer – measures temperature Spring Scale – measures weight Calculators and Computers – organize data and make graphs. Bunsen Burner – a source of gas heat Tongs – used to grasp heated material Hot Plate – a source of electric heat Fume Hood – used to contain and safely remove hazardous gases from the laboratory Tripod – holds glassware above a Bunsen burner Wire gauze – usually goes on top of tripod to hold the glassware being heated.

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Safe Laboratory Procedures Handling Chemicals Using Bunsen Burners Laboratory Glassware