Hey everyone. I've been attached to the Biochemistry section of the lab for the about 2 weeks. And it's one of the busiest sections here in the lab as many tests are done in this section. Examples would be Glucose test, Liver Function tests, etc.
Here in the lab where I work in we use the Beckman Coulter Synchron LX 20. It is a fantastic analyser that can run multiple tests at any one time in closed tube samples.
Retrieved 16 August 2008 from http://www.beckmancoulter.com/products/instrument/genchem/images/LX20_PRO.jpg
What is albumin?
Retrieved 16 August 2008 from https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgCmnBjCtCgTBDU-u-6fqJhQNd24WBjTUdyghTQs_Bfy2gmiG4NiAgJYRrmVa6O4aivvVVI2Ilb0KnYxw069T1V62tZkm8CaZ9AQFIZF63tzEX8qWZjT33NrflJ5zmNDcB3uJguAN428HxF/s240/Human+Serum+Albumin+Image.jpg
It is a carbohydrate-free protein that makes up 55-65% of the total protein and has a molecular weight of 69,000. It helps to maintain oncotic plasma pressure and is also involved in transporting and storing of ligands. It is also a carrier of unconjugated bilirubin.
Conditions related to albumin
Hypoalbuminaemia
This occurs when albumin levels are lower than the reference range.
However, hypoalbuminaemia can be related to multiple causes.
They can be related to:
liver failure/disease
tissue damage (during burns)
Crohn's disease (malabsorption of amino acids)
nephrotic syndrome (proteinuria)
neoplastic disease (protein loss from the stools)
The most common cause is of course, liver failure.
When there is liver damage, the hepatocytes fail to produce albumin. this then leads to a drop in serum albumin levels. However, albumin levels are not a good indicator of liver failure in the early stages as it has a long half-life, which is about 20days.
Now I shall share with you how the LX 20 machine measures the serum levels of albumin in a sample.
We use a Bromcresol Purple reagent, otherwise known as BCP (we can also use Bromcresol Green, but most labs use BCP, and Bromcresol Green is good when testing animal serum) 5 microliters of the sample serum (from plain tube that has been centrifuged at 3250rpm for 5minutes) is injected into 570 microlitres of the reagent. They will then react and combine to form bromcresol purple albumin complex.
Here in the lab where I work in we use the Beckman Coulter Synchron LX 20. It is a fantastic analyser that can run multiple tests at any one time in closed tube samples.
Retrieved 16 August 2008 from http://www.beckmancoulter.com/products/instrument/genchem/images/LX20_PRO.jpg
Of all the tests that is done in the Biochemistry section, I'm gonna highlight the Albumin test, which is one of the tests in the liver panel. In acute hyperalbuminaemia, there will be a low oncotic pressure and this will cause the blood capillaries to be permeable to water. Hence, this will result in edema.
What is albumin?
Retrieved 16 August 2008 from https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgCmnBjCtCgTBDU-u-6fqJhQNd24WBjTUdyghTQs_Bfy2gmiG4NiAgJYRrmVa6O4aivvVVI2Ilb0KnYxw069T1V62tZkm8CaZ9AQFIZF63tzEX8qWZjT33NrflJ5zmNDcB3uJguAN428HxF/s240/Human+Serum+Albumin+Image.jpg
It is a carbohydrate-free protein that makes up 55-65% of the total protein and has a molecular weight of 69,000. It helps to maintain oncotic plasma pressure and is also involved in transporting and storing of ligands. It is also a carrier of unconjugated bilirubin.
Conditions related to albumin
Hypoalbuminaemia
This occurs when albumin levels are lower than the reference range.
However, hypoalbuminaemia can be related to multiple causes.
They can be related to:
liver failure/disease
tissue damage (during burns)
Crohn's disease (malabsorption of amino acids)
nephrotic syndrome (proteinuria)
neoplastic disease (protein loss from the stools)
The most common cause is of course, liver failure.
When there is liver damage, the hepatocytes fail to produce albumin. this then leads to a drop in serum albumin levels. However, albumin levels are not a good indicator of liver failure in the early stages as it has a long half-life, which is about 20days.
Now I shall share with you how the LX 20 machine measures the serum levels of albumin in a sample.
We use a Bromcresol Purple reagent, otherwise known as BCP (we can also use Bromcresol Green, but most labs use BCP, and Bromcresol Green is good when testing animal serum) 5 microliters of the sample serum (from plain tube that has been centrifuged at 3250rpm for 5minutes) is injected into 570 microlitres of the reagent. They will then react and combine to form bromcresol purple albumin complex.
Albumin + BCP -----> Albumin-BCP Complex
The LX 20 then measures the change in absorbance at 600nm. This will be directly proportional to the concentration of albumin in the sample.
The reference range for albumin is 37-51g/L.
The reference range for albumin is 37-51g/L.
Therefore, to further diagnose liver failure, we have to run other tests as well as part of the liver function test and that includes testing levels of ALT, ALP, etc. For patients who are already diagnosed with liver failure, monitoring albumin levels allow us to see if their condition is worsening, and whether the medication prescribed has been effective. For example, if a liver failure patient's albumin levels continues to decrease over time, it probably indicates that more and more hepatocytes are continue to malfunction and have stopped synthesizing albumin.
Nevertheless, it is important that we run other tests as well to confrim before coming to any conclusion.
14 comments:
Other than a bromcresol Purple reagent, can we use other types of reagent?
Andika Putra
TG01
Hi Andika
As mentioned in the post, we can also use Bromcresol Green. But BCP is a more common reagent when testing human serum. And Bromcresol Green is used mainly for animals when testing animal sera.
Hi
May I know what are the other test(other than the one you mention) can the Beckman Coulter Synchron LX 20 use to measure.
Justina
TG01
0605950E
hey justina
There are so many tests, that the list will go on forever. But just to name a few,
it can test
microalbumin in urine samples
glucose levels in blood
liver function tests (albumin, alp, ast etc)
serum cortisol
phosphate levels
triglycerides for cholesterol, etc
Hello Elyana,
I have two questions to ask you,
1) Please describe the synthesis pathway of albumin and what are the effects of low albumin level in the body?
THanks
From: Benjamin MA
Class: Tg01
0606181F
Hello Elyana,
I have some questions for you:
1)What are the quality control procedures to maintain the Beckman Coulter Synchron LX 20?
2)What will happen to the body if chronic hyperalbuminaemia occur?
3)What are some examples of ligands transported by albumin?
4)What is the pathogenesis of Crohn's disease? What signs and symptoms will patient with this disease show?
5)Why is the long half life of albumin not a good indicator of acute liver failure?
6)Why do you measure changes in absorbance at 600nm but not at other wavelength?
7)How do you ensure you are only measuring albumin but not other proteins?
8)Do you encounter any difficulties when performing albumin test?
Thankz for your time in answering my questions! :)
Han Yang
TG01
Hi ely,
So it is actually significant if the albumin level is low, so what if it is high? Does it mean anything, like diease?
Thanks!
HEY ELYANA!!!
Just wanna ask what kind of machine do you use while doing the ALT, AST tests? Thanks.
Debo
TG02
hi han yang.
wow. the number of questions reminded me of the kind of questions i get in a term test.
since i'm at work now, and have limited time, I'll answer what I know on hand.
ANYWAY.
1) everyday, we run 3 sets of controls. one at about 9am, and another at 4am. at night we also run another control at around 11pm. if there is any discrepancy, we'll rerun the control, and look into the matter should be a need to
5) albumin is a good indicator but not that good as a predictor of early stage of liver failure because the long half life would prevent us from noticing any decrease in albumin levels at the early stages.
6) at 600nm, the machine is able to detect the molecular weight/size of albumin, hence the standard level.
7)other proteins have their own specific absorbance weight. for example, total protein is measured at 545nm. therefore, at 600nm, we only measure the levels of the albumin+bcp complex
8) so far there hasn't been any difficulties as this test is very much automated.
i'll answer the remaining qns over the weekend. :)
hi leslie,
the reason i didn't bring up high albumin levels because it's clinically insignificant.
so far there hasn't been a case of over production of albumin, and so hyperalbuminaemia is usually only related to dehydration.
when we're dehydrated, albumin levels will increase.
yo debo!
yup, we still use the Beckman Coulter LX 20 to test ALP and AST as well.
hey benjamin
the effects of hypoalbuminaemia is that it may lead to edema, kidney dysfunction and indicate liver failure. it may also indicate that the patient is not consuming enough protein, or is suffering from protein loss.
hi han yang. im sorry but i totally forgot to reply your remaining qns.
anyway, there has not been any threatening effects of hyperalbuminaemia that i know of yet.
as for crohn's disease, unfortunately, the exact etiology for this disease is still unknown. however, "Crohn's disease is a chronic, relapsing inflammatory condition affecting any part of the human gastrointestinal tract." (http://www.crohns.org/articles/2000_12_505-11_vm.htm)
this happens when there is inflammation with deep ulceration and there is a thickening fo the bowel.
environmental causes of this disease would be smoking. it has also said that genes play a role in the development of this disease.
signs and symptoms would be pain fever, and frequent diarrhoea. the patient may also suffer from joint pains, ulcers in the mouth, and reddening and inflammation of the eye (iritis)
Keep up the good job. You went to read up and tried to answer to questions posed by Han Yang. i hope you don't find it a chore to do because you will also learn in the process of finding out answers that you also unsure.
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