medical laboratory technology

1. Capillary electrophoresis
Adarsh Benny

2. •Principle
•In capillary electrophoresis, separation is done
within a capillary tube under high voltage and
high pressure, to give better resolution in
shorter time

3. Working
•Capillary ELP apparatus contains a long capillary tube
•Tube is filled with a sample solution
•Both the ends of tube are dipped into the buffer
•Two electrodes are dipped in buffer, and are connected to
power bank
•High voltage is applied

4. Buffer
Choice of buffer
• Should not interfere with analysis
• Should produce desired separation
• Should maintain buffering capacity throughout the
procedure

5. Sample injection
1) High voltage injection
• Buffer reservoir at positive electrode (anode) is
replaced by a reservoir containing sample.
• Sample is introduced into capillary by applying high
voltage
• Sample reservoir is then removed, the buffer reservoir
is replaced
• Voltage is applied, separation begins

6. • 2) pressure injection
• Capillary tube is removed from anodic buffer (+ve)
reservoir and inserted into an air-tight seal into the
sample reservoir
• Sample solution enters the capillary tube by pressure
• Capillary tube is then removed, replaced in anodic
buffer
• Voltage is applied, separation begins

7. •During electrophoresis migration, charged
molecules move towards opposite charge
•Separated molecules are detected by detector
•Signal is recorded by recorder

9. •Detector
•UV detector

10. Applications
•Separate aminoacids
•Separate proteins
•Separate drugs

11. Advantage
•Increased resolution
Disadvantages
•Sample sticky to capillary tube wall