I’m assigned to be at the thalassemia lab for 3 weeks. The most common test requested is the Haemoglobin (Hb) electrophoresis test. This includes the alkaline cellulose acetate electrophoresis test, Hb-H screening test and the variant test.
The purpose of alkaline cellulose acetate electrophoresis is to screen for Hb variants (Hb E, Hb S, Hb F, Hb A). The variation in the amino acid content of the different Hb causes variation of net charge of each Hb type. This hence determines their rate of mobility. When run, the Hb bands will appear accordingly. Any variants detected is followed up with acid gel electrophoresis (to distinguish Hb C) or other tests.
QC of alkaline cellulose acetate electrophoresis:
1) Known Hb A,F,S and E controls are run on the first well of each gel plate.
Hence, this acts as a reference to determine what variant the bands represent.
Applicator used to "pick up" the samples.
The wells where the samples will be pipetted into. the applicator will then be placed into the wells to "pick up" samples
Electrophoresis buffer tank. The bigger columns on the top and bottom is filled with fixed amount of supre-heme buffer. The gel strips will then be placed on top of the centre columns.
An example of an alkaline cellulose acetate electrophoresis strip. The bands are as indicated by the arrows (controls).
The Hb-H test is performed to screen for presence of Hb-H inclusion bodies.In this test, 2 drops of brilliant cresyl blue stain is added to 100 microlitres of blood. After incubation period of 1 hr at 37 degree celcius, samples are left to cool before smears are made for microscopy viewing. Presence of Hb-H is indicated by “golf-like” cells.
smearing of slides to screen for Hb-H. Notice that the colour of the smear is green due to the stain. The stain is bluish in colour at first. But it turns green when dried.
Picture taken from http://www.cuhk.hk/med/paf/slides/hematolo/xv-18.htm
The variant test (automated) is used to determine the percentage of Hb A2 and F. The machine used is the Bio-Rad variant beta-thalassemia short programme.
The purpose of alkaline cellulose acetate electrophoresis is to screen for Hb variants (Hb E, Hb S, Hb F, Hb A). The variation in the amino acid content of the different Hb causes variation of net charge of each Hb type. This hence determines their rate of mobility. When run, the Hb bands will appear accordingly. Any variants detected is followed up with acid gel electrophoresis (to distinguish Hb C) or other tests.
QC of alkaline cellulose acetate electrophoresis:
1) Known Hb A,F,S and E controls are run on the first well of each gel plate.
Hence, this acts as a reference to determine what variant the bands represent.
Applicator used to "pick up" the samples.
The wells where the samples will be pipetted into. the applicator will then be placed into the wells to "pick up" samples
Electrophoresis buffer tank. The bigger columns on the top and bottom is filled with fixed amount of supre-heme buffer. The gel strips will then be placed on top of the centre columns.
An example of an alkaline cellulose acetate electrophoresis strip. The bands are as indicated by the arrows (controls).
The Hb-H test is performed to screen for presence of Hb-H inclusion bodies.In this test, 2 drops of brilliant cresyl blue stain is added to 100 microlitres of blood. After incubation period of 1 hr at 37 degree celcius, samples are left to cool before smears are made for microscopy viewing. Presence of Hb-H is indicated by “golf-like” cells.
smearing of slides to screen for Hb-H. Notice that the colour of the smear is green due to the stain. The stain is bluish in colour at first. But it turns green when dried.
Picture taken from http://www.cuhk.hk/med/paf/slides/hematolo/xv-18.htm
The variant test (automated) is used to determine the percentage of Hb A2 and F. The machine used is the Bio-Rad variant beta-thalassemia short programme.
posted by SyafiqaH at
9:25 PM
2 Comments:
yes, im in haem lab. We'll take turns to go to thalassemia lab, bone marrow morphology lab, coagulation lab, routine lab and flowcytometry lab.
By
SyafiqaH, at 6:11 PM
Hello Gen!
Hb H, or Haemaglobin H, is usually present in patients with alpha-thalassaemia, where there is lack of alpha globin chains (quantitative deficiency). This is usually a genetic disease. If there is only a few Hb H inclusion bodies present, it may not be clinically significant. Hb H disease is apparent if the Hb H amount reaches to 85%
By
SyafiqaH, at 12:15 PM
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