Glassware and volumetric pipette.ppt

Glassware and volumetric pipette

1. Glassware and volumetric pipette

2. Glassware
Glassware can be divided into 2 groups
–Non-volumetric glassware
Beaker
Flask
–Volumetric Glassware
Volumetric Flask
Graduated Cylinder

3. Beaker
Used for transferring liquid to another
container or to transfer a small amount of
reagent for use in procedures.
Volume is not accurate, just an estimate.
NEVER PLACE A REAGENT IN ANOTHER
CONTAINER WITHOUT LABELING THE
CONTAINER FIRST.

4. Beaker

5. Erlenmeyer Flask
Features a conical base, a cylindrical neck
and a flat bottom.
They are marked on the side (graduated) to
indicate the approximate volume of their
contents.
This is NOTused for ACCURATE
measurement

6. Erlenmeyer Flask

7. Graduated Cylinder
For rapid measurement of liquid volume.
They are generally more accurate and
precise for this purpose than flasks.

8. Graduated Cylinder

9. Volumetric Flask
A volumetric flaskis used to measure very precisely one
specific volume of liquid (100 ml, 250 ml, etc., depending on
which flask you use).
This flask is used to prepare a solution of known
concentration.
To make up a solution, first dissolve the solid material
completely, in less fluid than required to fill the flask to the
mark.
After the solid is completely dissolved, very carefully fill the
flask to the mL mark.
The top is then sealed and the flask is inverted several times
to mix.

10. Volumetric Flask

11. Reading the Volume
10 mL has approx 6.62 mL
100 mL 52.7 mL
25 mL has 11.5 mL

12. Pipettes:
Laboratory instrument used to transport a
measured volume of liquid.
Three types of glass pipettes used in the
laboratory
–Volumetric
–Mohr
–Serological
Mechanical (automatic)

13. .

14. Proper Use
When filling a pipette, the tapered end is held
beneath the surface of the liquid at all times.
The liquid is drawn into the pipette by suction
until the level is equal to or greater than the
volume of liquid to be delivered.

15. What volume does this pipette
contain?

16. Proper Use
# When reading the volume,
ALWAYSview the pipette dead-
on at eye level with the pipette
held vertically, perpendicular to
the ground.
# Pipettes are designed to be
used with a hand pump or bulb,
of which there are many
varieties.
Never use your mouth with a
pipette!

17. Mechanical (automatic) pipettes:
Are medical and scientific laboratory
equipment used for dispensing small
quantities of fluids and liquids.
It has movable parts made up of steel and
plastic and uses a detachable tip to hold the
samples.
Micropipettes work on air displacement .

18. .
Have many different volumes ( 5 µL,
10µL,50µL ,100µL ,1000µL and 2000µL).

19. Proper Use:
10 steps :
1/ pre-wet the pipette tip.
2/ work at temperature equilibrium .
3/ examine the tip before dispensing sample .
4/ use standard mode pipetting.
5/ pause consistently after aspiration .
6/ pull the pipette straight out .

20. .
6/ pull the pipette straight
out .
7/ minimize handling of
the pipette and tip.
8/ immerse the tip to the
proper depth.
Pipette
volume
Immersion
depth
0.1µL 1-2 mm
10-200µL 2-3 mm
200-2000µL 3-6 mm
2000µL and
more
6-10mm

21. .
9/ use the correct pipette tip.
10/ use consistent plunger pressure and speed.

22. .