RUSY'S SIP

Hey all of you out there!!! I hope you guys are doing great at your respective attachment sites. As for me, I’m attached to Centre for Transfusion Medicine (CTM). And I can tell you guys that I am having a great time at the blood bank.

For the first three weeks, I have been attached to the cross-match and red cell reference (serology) labs. And now, I shall share with you one of the important tests that I had observed.

Subject Title: Blood Banking
Name of Test/Topic: Antibody Screening

In the cross-match lab, AbSC is done on almost every new blood sample that arrives. This is because there may be samples from previous patients with a record of medical history. For these people, AbSC is done only if the previous screening was done more that three days from the current date.

For example: First sample of patient arrives on 1^st July (Tuesday), and AbSC is done. The next sample arrives on 3^rd July (Thursday). AbSC is not done for this sample, as the time period for this sample from the previous one is only two days. Another sample arrives on 5^th July (Saturday) and this sample is then allowed to run an AbSC.

The reagents needed for AbSC are SPO (Singapore Panel O) cells, and plasma/serum of the patient. The SPO cells are prepared in-house by one of the senior lab officers. In CTM, three panels are used, compared to the two panels that we use in school.

In this lab, antibody screening is automated with the help of a machine called Techno TwinStation. Blood sample is to be centrifuged upon arrival to separate the plasma from the cells. The samples are then loaded into the machine where antibody screening will automatically commence. The machine uses the principle of AHG phase AbSC (antibody sceening) as it uses gel cards, which contain coombs’ reagent. The incubation of the reagents is also done in the machine. As soon as the process is over, the machine will produce the results on the touch-screen attached to the machine.

In the serology lab, AbSC is done manually. There are two phases of AbSC: saline phase and AHG phase.

For saline phase, cells and serum are mixed in a tube in a ratio of 1:2 (1 drop SPO cells, 2 drops patient serum). The reagents are allowed to react in room temperature for 30minutes, before spinning them at 3000rpm for 15seconds. This phase is for detection of cold antibody, mainly IgM.

For AHG phase, the gel cards are also used. However, the reagents are manually pipette into the wells of the card, where sensitization occurs during a 15minute incubation at 37^oC. The ratio of cells to serum when using the gel card however is reversed 2:1 (50ml SPO cells to 25ml patient’s serum). This is because weak antigen may not be detected if there is a higher amount of cells than serum in the gel card. After incubation, the cards will be spin down at the speed of 1000rpm for 10minutes. RBC agglutinates will be filtered through the column of gel according to size. A negative reaction will show that all the red cells are settled to the bottom of the column, while positive reactions will produce cells within the gel. This phase is for detection of warm antibody, mainly IgG.

After antibody screening is complete, antibody identification can be done to identify presence of specific antibody.

Techno TwinStation

Retrieved from: http://www.diamed.com/product_detail.aspx?id=848&navvis=

Coombs Anti-IgG gel cards

Retrieved from: http://www.diamed.com/product_detail.aspx?id=82&navvis=

I hope that all of you readers have gained some knowledge from my entry. Just shoot any comments and I will try my best to reply as soon as possible.

taking cares
peace out

Name: Rusydiana binte Kusni

Class: Tg 02