Sunday, June 28, 2009

1st Week of Attachment (:

Hi everybody! (:

I am attached to this Hospital where we get ourselves rotated to different departments/sections/disciplines. But eventually, I think we'll be in the section where we are first rotated to. Anyway, the different departments/Sections are:

1. Haematology
2. Biochemistry/Immunology
3. Microbiology
4. Administration - Involved in registering the specimens, etc.

So, I'm attached to the Biochemistry/Immunology Section.

____________________________________________________________________

Subject Title: Clinical Chemistry

There are a few tests I learnt this week. But for this post, I'll just post on one of the tests which is conducted everyday.

Name of test: Microalbumin Urine Qualitative Test

This test is usually carried the most in the morning (as morning is the time when specimens come in) and in the late afternoon at about 4.30pm (where it is also the time when specimens arrive).

Principle(s)

Microalbumin Urine Test is used to check whether the patient's urine contains albumin and creatinine. As you know, Albumin is a plasma protein which is found in the blood. It is filtered by the kidneys. Under normal conditions, albumin is not supposed to be present in the urine as the kidneys would have filter the albumin and albumin would be reabsorbed back into the body. Only very low amounts of albumin is present normally. So, if albumin is seen in the urine, this would indicate that the kidneys are not effective in filtering albumin and kidney damage is plausible.

The Clinitek Status Microalbumin Machine consists of a test table. The test table contains a sensor which will detect the reagent strip and the machine can then start the test.

Reagent Strips are used. They are firm plastic strips that contain 2 reagent areas testing for albumin and creatinine in the urine. These strips are read using Clinitek Status® Analyser. A albumin-to-creatinine ratio is determined too in mg/g or mg/mmol. The reagent strips provide semi-quantitative results and these serve as screening test for microalbuminuria.

Chemical Principles:

Albumin = test is based on dye binding using high affinity sulfonephthalein dye. At constant pH, blue colour is developed due to albumin. Colour ranges from pale green to aqua blue.

Creatinine = test is based on peroxidase-like activity of a copper creatinine complex which catalyses the reaction of diisopropyl benzene dihydroperoxide & 3, 3', 5, 5' - tetramethylbenzidine. Colour ranges from orange through green to blue.


Materials used for this test

1. Urine Sample in Dry Container
2. Microalbumin Machine (Clinitek Status)
3. Paper towels (These are to put on the table to prevent spillage of urine on table directly)
4. Biohazard Bag (To discard the used reagent strips)
5. Clinitek Microalbumin Reagent Strips
6. Gloves


Picture of Clinitek Status
® Analyser:









Taken, 28th June, 2009, from
http://images.google.com.sg/images?q=clinitek%20status&oe=utf-8&rls=org.mozilla:en-GB:official&client=firefox-a&um=1&ie=UTF-8&sa=N&hl=en&tab=wi


Picture of Clinitek
® Microalbumin Reagent Strips:








Taken, 28th June, 2009, from
http://images.google.com.sg/images?hl=en&client=firefox-a&rls=org.mozilla%3Aen-GB%3Aofficial&um=1&sa=1&q=clinitek+reagent+strips&btnG=Search+images&aq=f&oq=


Method

1. Check that the Patient’s name on sticker label on the cap is the same as the label pasted around the bottle. If it is wrong, it is given back to the administration section.

2. Press "Strip Test" followed by "Enter New Patient'' on the analyzer.

3. Key in Patient's Lab Request Number and press "Enter".

4. Take out one reagent strip from the bottle and dip it briefly and completely into the urine

5. Place it on the test table and ensure that the tip of the strip touches the sensor.

6. Press "Start" on analyzer.

7. Record Results

8. Press "done"

9. Discard the used strip

10. Wipe the test table with paper towel after every test for each urine sample to prevent urine buildup.


Results

Expected results:

Albumin = < 20mg/L (Normal)
20mg/L - 200mg/L (Microalbuminuria)
> 200mg/L (Clinical Albuminuria)

Creatinine = <10mg/dl (Normal)
10 - 300mg/dl (Microalbuminuria)

Albumin-to-Creatinine Ratio = < 30 mg (Normal)
30 - 300mg/g (Microalbuminuria)
> 300 mg/g (Abnormal & Clinical Albuminuria)

Note: We are to print out a worksheet first before we conduct the test (any test for that matter). On the worksheet, in this case, if the urine is normal, we record "Negative" or "Neg". If the urine is abnormal, we record ''Abn".

For Abnormal or highly abnormal urine, the following steps are applied:

a) Pour the urine into a tube
b) Spin down using Cnetrifuge machine
c) Order for quantitative test using Cobas Machine.


Done By:
Rebecca Chew
0703363B

12 comments:

  1. Hi Rebecca ^^
    Thanks for the very detailed entry, yay!

    Btw, could u explain more about Microalbuminuria and Clinical Albuminuria? Are they totally 2 different types of Albuminuria or they occur one after another? =D

    And.......I'm just curious about the analytical sensitivity of Clinitek Status® Analyser, such as what's the minimum value it can measure?

    Vo Thu Hong Anh [Jess]

    ReplyDelete
  2. Very good and detailed posting. Why is creatinine testing required in this test? The main purpose is to test the presence/absence of albumin? What is the importance of measuring creatinine and obtainin the ratio?

    ReplyDelete
  3. Thanks Miss Chew and Jess for your comments (:

    Answers to Miss Chew:

    Creatinine testing is required in this test in order to make the test more accurate. Albumin levels vary throughout the day.

    The main purpose is to test the presence of albumin.

    After measuring creatinine, we can then calculate the ratio. This is important so as to compensate for the variations in urine concentration during the day. Ratio is important as it determines the GFR which helps to screen for any kidney damage.

    Answers to Jess:

    Basically, both Microalbuminuria and Clinical Albuminuria are conditions of having albumin in your urine. The difference is with regards to the levels of albumin and creatinine and the ratios. Clinical Albuminuria has higher levels of albumin and creatinine than Microalbuminuria. Yes, you're right in saying they occur one after another if not treated.

    hmm..as for the analytical sensitivity, I can't seem to find the answer. I'll go and ask my colleagues and I'll reply you again (:

    Btw, Miss Chew, can post online blackboard the blog addresses of all the groups?

    ReplyDelete
  4. Hi Rebecca,

    what do you mean by abnormal urine? Does it only mean abnormally HIGH urine results are considered as abnormal or abnormal can also be referred by the colour of urine?

    From the chemical properties heading, I understand that albumin and creatinine are measured by using dyes specific to them respectively. Does it mean that the analyzer measures the intensity of the dyes? (what I mean is: eg if the urine sample has a high concentration of albumin, this will be shown by a high intensity of the dye.) ??

    Have a good time at work!! (:

    Cheers,
    Lim Jia Hui
    02nd July 2009; 09:18AM

    ReplyDelete
  5. @ Rebecca: thanks for the answer yo! =D no hurry, take ur time to find out the analytical sensitivity, lolz, not so significant =D
    btw, u can go to my group's blog, we have all other groups' links, ehhehe

    Groups6: http://med-scientist-in-action.blogspot.com/

    Vo Thu Hong Anh [Jess]
    0705364H

    ReplyDelete
  6. JESS!

    I went to ask my colleague and he didn't know the term "analytical sensitivity" at first. haha! Anyway, Clinitek Status is for QUALITATIVE test only. It only detects whether albumin is present in urine or not. So, the lowest measurement will be NORMAL. But as for the machine that runs quantitative microalbumin test, the analytical sensitivity is 3mg/L. The machine is Cobas 501.

    Answers to Joey:

    Hi Joey!

    Highly abnormal or abnormal urine is still considered "Abnormal" Urine. Actually I did ask my colleague a similar question too. But I went and observe the colour of the reagent areas on the strip and I don't see much of a difference in the colour between normal and abnormal urine. And also, the gross appearance of urine not very accurate in determining whether abnormal or normal. Some of the colour look similar yet one can be normal and the other abnormal. But sometimes, a clear coloured urine tends to be abnormal.

    As for your second question, I'll post again. (Now I abit sleepy already hehe)

    ReplyDelete
  7. @ Rebecca: hahaha, thanks for the info. Btw, I just wonder, if Clinitek Status is only used for qualitative test, then how to differentiate between Microalbuminuria and Clinical Albuminuria? Coz the 'results' part with different expected values is for Clinitek Status machine, rite? lolz.

    Vo Thu Hong Anh [Jess]
    0705364H

    ReplyDelete
  8. Hi! Is there a difference between abnormal and clinical Albuminuria? If yes, what's the difference and yet the value (> 300 mg/g) the same? If not, what's the significant of the 2 different terms (clinical/abnormal)?

    Goh Michelle

    ReplyDelete
  9. Hi Rebecca,

    Is there a turnaround time for the samples that you do? How long is it?

    Thanks.

    Zhang'E
    TG02
    0704086H

    ReplyDelete
  10. Hey Rebecca!

    Can you do microalbumin test on overnight specimen? Because urine FEME is only done on fresh specimen, but what if they want a additional test for microalbumin? Microalbumin is also done for 24 hour urine right? XD

    Hui Juan
    0702012F

    ReplyDelete
  11. To Zhang'E:
    Hi (: yea there is a stat (short turn around time) for microalbumin. So far, I only came across 1 specimen with "stat" haha. So for stat specimen, the result must be out within 30 minutes.

    To HuiJuan:
    Usually Microalbumin test is done in the morning and afternoon. Well, of cos all of us CAN do microalbumin test if specimens do come in at night. But first-morning specimens are recommended for microalbumin tests. Eh, by the way, aren't overnight specimens morning specimens? After 12am, it's considered morning hahas. Usually, for 24 hour urine, so far based on my experience, I didn't do any microalbumin test.

    ReplyDelete