BOOM BOOM BOOM!

Moshi Moshi everyone,

For the first three days of my SIP,i was attached to Haematology lab. The first thing i was told to do was to learn how to make a peripheral blood film. There is a very senior med tech, Mr Yeo, who demonstrated and explain the technique to me. He make around 5 slides for me to see and i thought to myself; 'seemed easy to me, should not be a problem'. But i was wrong, i tried it myself and it doesn't turn out to be easy as i either make a edgy or too thick or too thin film. Then i remembered why during one of the E-lecture for haematology, Mr Poh mention practice until you know to how to make a blood film... because most of the staffs there mentioned that they take some time to practice to perfect it. A well made blood film should be thick at the drop end and becomes thinner at the other end. Most importantly, the glass spreader should be clean and dry because if it is wet,it may cause lysis of red blood cell.


Although i only have 3 days at Haem lab but i think i learnt quite a few tests; Kleihauer Betke test and dengue serology

Kleihauer Betke Test.
is a test used to access the degree of Foetal Maternal HAemorrphage(FMH) via detection of foetal red blood cells in maternal peripheral blood.

Method:
1) 3 different smears are made: a)negative control
b)Test sample
c)Positive control
2) Air dry the smears

3) Fix the smears in solution C( ethanol) for 10mins

4) Stain the slides in elution solution ( consist of solution A,B &C)for 20sec and rinse with tap water.
*solution A- 0.75% Haemotoxylin in 96% ethanol
solution B- 2.4g of ferric chloride in 0.5% hydrochloric acid
solution C- 80% ethanol

5) Counterstain the slides with Eosin B for 3 mins, wash with tap water and air dry.


Results:

Foetal red blood cells will appear as darkly red stained cells while adult RBC will appear as palely stained ghost cells.
If there are more than 10ml of foetal RBCs in maternal circulation, it is clinically significant.

Dengue serology:
I was fortunate to perform the test under the guidance of a staff. The test is carried out in the biohazard safety cabinet. There is this commercial kit called Dengue Duo Cassette, which allows presumptive differentiation between primary and secondary infection via detection of IgM and IgG antibodies respectively. This kit is easy and also convenient as the result is known in 15mins.

Picture of a Dengue Duo Cassette:

Taken on 4july 2009 from: http://www.pacbiotekindo.co.id/products/dengueduo_cassette.html

Principle: The principle is based on binding of dengue-specific IgM or IgG antibodies present in the patient sample to the anti-human IgM or IgG antibodies embedded on the cassette membrane. There is also a control to ensure the test is carried out correctly.

Method:
1) Add 10ul of serum to the circular well via a micropipette
2) Allow the sample to absorb entirely within the circular well
3) Holding the buffer bottle vertically, add 2 drops of buffer to the square well at the base of the cassette.
4) After 15mins, read the result

Result:
Any trace of pink line in the test area shows a positive result.
Primary infection: Pink band in the IgM & Control region
Secondary infection: Pink band in the IgG,control region and/or IgM region.

For now that is all about it,hope everybody will have a glimpse or some idea how dengue is detected=)

Signing off
Yong Herng
TG01
The Sesame