Pipettes and Glassware Flashcards
What kind of pipette has been calibrated to deliver a fixed volume of liquid by drainage, and are used when volumes of liquid are to be delivered with great accuracy?
volumetric or Ostwald transfer pipette
Which pipette delivers full volume from mark to mark on its stem?
Mohr graduated pipette
What kind of pipette delivers full volume from mark to tip?
serological graduated pipette
What type of volumetric pipette would be used to deliver an aliquot of whole blood?
Ostwald-Folin
What distinguishes a pipette as a “blow-out” variety?
1-2 frosted rings, or other type of etching at the top of the pipette
What kind of flask is the most precise kind, used to prepare specific volumes of reagents or laboratory solutions?
volumetric or Florence flasks
What kind of flask is used to prepare reagents that do not require precision and accuracy?
Erlenmeyer
What do T.C. and T.D. stand for?
to contain, to deliver
Why is low-actinic glassware used in the laboratory?
its amber coloring protects light sensitive compounds
What is the most common material for plasticware in the laboratory?
polyethylene
What solutions may be used for cleaning dirty or stained glassware that resists normal cleaning?
potassium dichromate (K2Cr2O7) or calcium dichromate (CaCr2O7) and sulfuric acid (H2SO4)
What are five items of calibration information that can be obtained from a pipette itself?
volume delivered at calibration mark; degree of uncertainty; Class designation (Class A means it conforms to specifications of the National Bureau of Standards); calibration mark is etched onto tube; whether it is T.C. or T.D.
At what temperature is most volumetric glassware calibrated?
20*C
What liquids should be pipetted with a volumetric pipette?
whole blood, serum, standard solutions, some reagents
What is the curvature in a liquid’s top surface when placed into a container such as a pipette?
meniscus
