Centrifuge
Centrifuge
sediment particles [cells ,bacteria ,casts, parasites]suspended in fluid by
exerting a force greater than of gravity.
Centrifuge
force: It is the greatest outward pull due to rotation . the more (rapid) centrifuge force effective the
more sedimentation. Heavy particles sediment first followed by the lighter
particles .Centrifugal force increases with the speed of rotation.
The
actual sedimentation achieved at a given speed depends therefore on the radius
of the centrifuge.
Centrifuge in the district laboratory:
1.General purpose bench
centrifuge
2.Microhaematocrit
centrifuge.
Function of general bench purpose centrifuge:
1.To sediment cells ,
bacteria and parasites in body fluids for microscopic examination ,e .g.,blood
,urine ,CSF.
2.To obtain serum wash
red cells and perform emergency compatibility testing (cross watching)
3.To perform parasite
concentration techniques.
4.To obtain serum or
plasma for antibody testing and clinical chemistry tests.
Function of microhaematocrit centrifuge:
1.To diagnose and
monitor anemia when a reliable measurement of hemoglobin is not present.
2.To measure PCV to
calculate MCHC in the investigation of anemia.
3.To perform
microhaematocrit concentration techniques to detect motile trypanosomes and
microfilaria.
Use and care of centrifuge:
1.Place the centrifuge on
a firm level bench out of direct sunlight towards the back of the bench , Leave
a clear area of 30 cm around the centrifuge.
2.Read the
manufacture’s instruction , prepare a
stock record card and written sops covering the use cleaning and maintenance of
the centrifuge .
3.If using glass tubes
use round bottomed tubes.
4.Do not overfill tubes
or containers unless using a sealed tube holder.
5.Do not insert a cotton
wool pug or other loose fitting bung in a tube.
6.Check that the bucket
or tube holders are correctly positioned in the centrifuge.
7.Make sure that the
contents on each side of the centrifuge are balanced.
8.Do not operate the
centrifuge at a higher speed than that recommended for the rotor.
9.Make sure that the
speed control of the centrifuge is set at zoo before stating Always increase the seed slowly.
10.Do not operate the centrifuge at a higher
speed than that recommended for the rotor .
11.If centrifuge is not
fitted with automatic brake, do not stop the rotor by this.
12.Never open the
centrifuge until the motor has stopped and the rotor has stopped spinning.
13.Turn off the
centrifuge and remove the plug after each day work
Clean the centrifuge and tube holes weekly or if indicated.