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.
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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
