Neonatal Bilirubin

Hello all~! Yan Ling here~! Sry for the late post. ><

Can u believe? We had finished 16 wks of sip le~! 1 more mth to go~! xD

Okay for this post, which should be my last post already, I'm going talk about neonatal bilirubin testing. I'm was sent of a medical center somewhere in sg where they do neonatal bilirubin testing as there are nurseries there. Believe everyone should still remember abt the incompability of mother-fetal bld group, which result in hemolysis of fetal's RBC by mother's IgG.

When the fetal's RBC are broken down, bilirubin as the by-product was produced and is to be removed by the fetal's liver. However, when the amounf of bilirubin exceeds the theshold of the liver to remove the bilirubin, it will remain in the body, and thus resulting in neonatal jaundice. And to treat the neonatal jaundice is by giving phototherapy so the light, usually blue in colour, will break down the bilirubin.

And so, measuring the amount of bilirubin in the baby's serum is important so to see if he/she requires any treatment or able to go home with his/her mummy.

First, the collection of baby's blood is using heel prick where the phlebotomist will use a lancet to prick the either side of the baby's heel and using a capilliary tube to collect the blood. After that, the tube is spin down to get the serum. The centrifuge used is different from the normal ones we see/uses in the lab, its especially for spining down capillary tube, however, using the normal centrifuge is also possible but it requires longer spining time compare to the special centrifuge which usually requires abt 3-4 mins to spin down.

So after the tube is been spun down, it will be separated into serum and RBC. Then, the serum part will be used to read for the neonatal bilirubin. The analyser used in my lab is reichert, which

uses a curvette to read the amount of bilirubin.

The principle of this test is spectrophotometer which measures the colour of the serum. The machine measures at 460nm and 55onm. At 460nm, the machine will measure the bilirubin and oxyhemoglobin and at 550nm, the machine will only measure the oxyhemoglobin. And thus the difference of 460nm and 550nm concentation will be the total bilirubin. Since oxyhemoglobin is measured, hemolysed specimens will not affect the result since the hemoglobin is measured.
The values of the bilirubin are then faxed to the clinics/nurseries where the doctors will decide whether to continue the treatment or not.

Here are some pics to show you about the machine. xD

The Reichert machine with curvette, and the syringe-looking thing is to add the serum into the curvette.


Capillary tubes with babies' blood after spun down.

Thats all. xD Feel free to ask me any questions. Will try to answer wor. ><

yaNLing xD

Biochemical Test

Hi!

I was posted to the Anerobic(Quality control)on my 16th week.And we have been doing Biochemical test for the identification of Bacteria. The bacteria identification test done for the post is for E.coil

Biocehmical test is used for the identification the bacteria, by using the biochemical propaty of the bacteria. It is done using the following basic media.

Kliger iron agar

It uses the ablity to utilise carbohydrate fermentatively & to librate H2S.It contains one part glucose (0.1%) and 10 part lactose (0.1%).Phenol red is used as pH indicator.H2S formation is by the reaction of bacterium with sodiumthiosulplate with will form ferrous sulphide when H2S reacts with ferric ion.


Simmons citrate agar

Organism utilise citrate as their sole carbon source which is a intermediate metabolite in the kerb’s cycle. Media contain inorganic ammonium salt which the organisum use as a sole nitrogen source. The presence of organisum utilise the media a creats a alkaline environment that turns the bromthymol blue to a intense blue when pH reaches above 7.6.

Typtophan broth

The indole test determines the ability of an organism to produce indole from the degradation of the amino acid tryptophan in the broth. Tryptophan is hydrolysed by tryptophanase to produce three possible end products which is the Indole, pyruvic acid and ammonia.A bright red color product is produced when the indole is combined with aldehydes group.

Oxidation Fermentation (OF) basal Medium

The medium contains a high concentration of added carbohydrate to avoid the utilization of peptone by an aerobic organism as it would neutralize slight acidity produced by an oxidative organism.Bromthymol blue is used as a indicator.The agar permits the determination of motility and aids in the even distribution of any acid produced at the surface of the medium



Inoculation Method and reaction

Kliger iron agar

Stab to the bottom of the tube and streak the slant
Acidic butt and slant: Glucose and lactose fermentation (E.coil)
Acidic butt and alkaline slant:Glucose fermentation,Lactose nonfermentation
Alkaline butt and slant: Glucose and lectose non fermentation
Black media for H2S production.
Bubble when other gas is produced


Simmons citrate agar

Streak the slant.
+ve: Growth on the slant or deep blue colour observed. (E.coil)
-ve: No growth and no clour change (remains green)


Typtophan broth
Inoculate organisum by dissolving the colony in the broth.
After 24 hrs of incubation add 5 drops of kovac to the inner wall to see the pink interface.
+ve: Bright fuschia red interface with in secs.(E.coil)
-ve: No change

OF basal Medium
Stab the organisum stright to till the ¾ of meduim.
+ve: Medium becomes yellow indicating acid production. (E.coil)
-ve:Remains green.
Motality is observed when organisum grow away from the stright inoculum line.(E.coil)

By

Shameema :)