M1 U3: Glassware, Equipment and Supplies Used in Clinical Chemistry Flashcards
Volumetric Flask
- class A quality
- calibrated to contain (TC) one specific amount or volume of liquid
- flasks label also indicated the nominal volume, tolerance, precision class and relevant manufacturing standard
- used to bring a given reagent to its final volume with the prescribed diluent
Erlenmeyer Flask
- aka titration or conical flask
- measuring, mixing, heating, but better suited for swirling solutions and can easily be held at the neck in one hand
- designed to hold different volumes rather than one exact amount
Beakers
- can be heated to much higher temperatures compared to plastic counterparts, higher clarity and content visibility and measuring
- graduated markings are accurate within 10%; not as precise as volumetric flasks or graduated cylinders
Graduated Cylinders
- more accurate and precise for measurement purposes than flasks and beakers but should not be used for volumetric analysis
- Plastic gc are impact resistant
- polyethylene gc are transparent
- polypropylene gc are chemically resistant
- Glass gc are chemically inert
- borosilicate gc greater resistance to thermal shock
Pipettes
- usually used for 20 mL or less; larger volumes are transferred or dispersed by automated pipetting devices or jar-style pipetting apparatus
- manual pipettes bulbs or pumps
- semi-automatic pipettes similar device built into it
- mouth pipetting, aspiration
Burettes
- used to dispense and measure a variable amount o a chemical solution in analytical chemistry at the same time
- stopcock valve
- Gas measuring burettes, stopcock is at the top of the glass tube
- Digital burettes, deliver at increasing accuracy and precision
Funnels
- Buscher and Hirsch funnels can remove fine particles from a liquid
- sintered glass frit is suggested for more demanding filtering applications
- Plastic, generally used for transferring powders
- polyethylene, aqueous solution transfers
- glass, inertness
- metal, won’t chip, break, corrode
Stirring Rod
- used to mix chemicals and liquids for reaction purposes
- glass with steel cores or in solid plastic
- chemically resistant, inert, and non-abrasive
- steel core, extra rigidity is required
- solid plastic, tapered end
- borosilicate, low thermal expansion values and feature flat ends
Glass Test Tubes
- most commonly and widely used lab glassware
- used to handle chemicals and allow you to observe the contents of the tube during the reaction
- 12 x 75 mm, containing samples (plasma or serum)
- 13 x 100 mm, containing protein-free filtrate
- 15 x 100 mm, containing distilled water or diluent for reagent preparation, whole blood for serum and protein-free filtrate preparation
Centrifuge Tubes
- used to contain liquids during centrifugation
- conical bottoms, help collect any solid or heavier parts of the sample being centrifuged
Cuvettes
- aka analytical cell or sample cell
- used to hold samples for spectroscopic measurement
- glass, suitable for visible region and routine UV work; greater transparency and accuracy of measurement
- quartz, UV far-infrared transmissions
- plastic, one use and do not require cleaning
- square, plane-parallel optical surfaces and a constant light path; advantage over round there is less error from the lens effect, orientation in the spectrophotometer, and refraction
- scratched surfaces should be discarded as they scatter light
Reagent Bottles
- excellent for storing powders and liquids
- tinted amber or red, protect light sensitive contents from UV light, visible light, and infrared radiation
- narrow mouths, better control while pouring
- wide mouths, easy filling or content retrieval
- caps or stoppers should be selected carefully, material or lining may interact negatively with the contents of the bottle
- plastic, glass, borosilicate glass, or soda lime glass
Thermometers
- utilization of laboratory refrigerators
- monitoring of temp of water baths, heating cells, and heating blocks
Liquid-in-glass thermometer
- measure between 20C and 400C
Calibration:
- calibrated against an NIST-certified or NIST-traceable thermometer
- SRM with calibration points (0, 25, 30, 37)
- calibrated against Gallium cell
Types:
i. Partial Immersion thermometer
ii. Total Immersion thermometer
iii. Surface Thermometer
Partial Immersion thermometer
used for measuring temps in units such as heating blocks or water baths
Total Immersion thermometer
used for refrigeration applications
Surface Thermometer
maybe needed to check temperatures in flat surfaces, such as an incubator or heating oven
Electronic Thermometer or Thermistor Probe
- small size and millisecond response time
- calibrated against SRM thermometer or the gallium melting point cell
- when calibrated against gallium cell, it can be used as reference for any type of thermometer
Digital Thermometer
- widely used
- overhauls and updates the traditional liquid-based thermometer
Syringes
- sometimes used for transfer of small volumes (less than 500 microliters) in blood gas analysis
- used in separation techniques such as chromatography or electrophoresis
Expected inaccuracies:
- < 5 microliter : 2% inaccuracy
- > 5 microliter : 1% inaccuracy
Rubber Bulb
- used with serological or volumetric pipettes
- silicone, natural or synthetic rubber
- allow safe, manual control of filling or discharging hazardous liquids
Parafilm/ Sealing Film
- thermoplastic, self-sealing film, it is ideal for the scientific laboratory
- stretchable, moldable, waterproof, and self-adhering, holds moisture loss to a minimum
- commonly used for sealing or protecting vessels as it offers excellent protection for the contents of tubes, flasks
Dessicants
- used to keep other chemicals from becoming hydrated
- most effective when placed inside a desiccator (closed and sealed containers)
- majority of which are hygroscopic
Hygroscopic
- substances that take up water on exposure to atmospheric conditions
- can remove moisture from the air as well as from other materials
Deliquescent substances
Substances capable of absorbing enough water from the atmosphere to cause dissolution
Hydrate
Compound with the associated water molecules
Anhydrous
When the water of crystallization is removed from the compound
Wash Bottles
used to supply precise and small quantities of various liquids
Test Tube Rack
help keep a lab organized and keeping test tubes up right
Disposable pipette tips
- designed to fit securely and tightly around a pipette barrel
- accuracy can be affected if not fit properly to the barrel
- poor seal, drawn-in air can escape and the correct volume of liquid is not aspirated