Electrophoresis: and micropipettes
It is a method of separating a mixture of organic compound,
The technique in used in separating protein like hemoglobin, serum protein,
lipoprotein enzyme. It is useful for detection of haemoglobinopathies.
Procedure:
Electrophoresis in the migration of charge
particle in an electrical field the protein has both amino and carboxyl groups
and carries (+) or (-) charge depending on whether the pH of the medium is
acidic or alkaline . At the isolectric point (a particular Ph) when the protein
bears equal amount of positive and negative charge and will move towards the
positive hole. During electric protein the Ph of the buffer is kept at 8.4 As
the mixture of serum protein is placed on a spot of a support medium and when a
current is passed different protein migrate at different rates.
Is electric point .this is because each has a different is
electric point. Location of the protein spot is determined by staining with a
protein staining dye.
Micropipettes:
The
micropipettes are continuously adjustable and detachable disposable tips. The
adjustable delivery volume is displayed digitally on a read-out window in the
handle .
Tip :
Tips are made of colored polypropylene conical aperture.
Parts of a micropipettes:
1.Grippe.
2.Handle with digital
display.
3.Operating button
4.Tip ejector pusher.
5.Tip ejector
6.Tip cone
Pipeting whole Blood:
1.Depress the operating
button to the first. Dip the tip under the surface of the liquid in the
reservoir about I can deep and slowly release the button. Withdraw the tip from
the liquid by touching against the edge
of the reservoir to remove excess liquid to fill the tip with blood and
wipe the tip with dry tissue.
2.Immerse the tip into
the reagent and depress the push button to the first stop and release but do
not lift it.
3.Repeat the
procedure in the reagent until clearing
the interior wall.
4.Finally depress the
button up to second stop.
Maintenance of micropipettes:
1.Store in a vertical
position.
2.Pipettes should be
checked at the beginning of each day.
3.It should be cleaned
by 70% ethanol.
4.Servicing should be
done at least twice a year while it is used daily.
Trouble:
Defect
Cause
Solution
(1)Leakage→ (a) Tip incorrectly→ The tip
Attached attach firmly
(b) FG between
Clean the
Tip and tip cone Cone
(2)Incorrect→ Incorrect→ Follow the instruction or
Dispensing Operation manual
correctly.
Pipette operation :
Delivery volume setting:
1.It is setting by
operating delivery button the tap.
2.It can be moved
clockwise and anticlockwise for increase or decrease the volume.
Do not set volume outside the pipette specified volume.