Monday, August 10, 2009

General Chemistry

It’s my turn to blog again after 5 weeks (: I’ll be sharing about the general chemistry section this time. I did specimen processing at this section so my good friends are Cobas, MPA and SWA. I also need to do basic housekeeping like cleaning the work area with 0.1 hypochlorite and refill consumables like hitachi cups daily. When I receive the blood and urine samples, I must first check that the name on the label and the tube matches before pasting the labels on the tubes. Before samples are processed, I also need to check if there is sufficient volume (at least half the tube is filled), have tests other than biochemistry and whether is it to be loaded on Cobas or SWA. When there is insufficient volume or needs to be loaded on Cobas, I will need to spin it offline (centrifuge manually). If not, I can just load the samples into MPA directly.

I will be sharing about my good friend, MPA, this week. MPA refers to Roche Hitachi Modular Pre-Analytics Standard B Plus. This piece of equipment helps to minimize our exposure to the blood samples. Sample tubes must be racked according to the tube height before loading into MPA. If different heights are placed together in a rack, the alarm will sound. There will be an alarm code and I can check on the chemistry computer to check the reason for the alarm. Samples are identified by LIS generated accession labels. Erroneous labels, labels that cannot be read or labels that are stick in such a way that the machine cannot rotate the tubes, the rack of tubes will be ejected via a rejection buffer for the operator to retrieve. Racks are placed in the Input Buffer Module (IBM) and are immediately transported to the Automatic Centrifuge Unit (ACU), which spins at 1800g for 5minutes or to a pre-centrifuge holding area if the centrifuge is full. This holding area also facilitates the ability for a subsequent urgent request to be inserted into the next available centrifugation cycle. After which, the racks move to the Destopper Module (DSP) to have the caps removed before samples proceed to the Online Aliquoter Module (AQN). At AQN, individual daughter aliquots are made for clinical chemistry, immunoassay, offline testing or archival. Daughter tubes for offline testing are labeled by an online labeler at the Barcode Labeler Module (BCL) and recapped if necessary (e.g. HIV specimens) at the Restopper Module (RSP) or recapped manually using cheap green caps. Before the samples enter BCC, the AQN will check if there is sufficient serum and whether there is any clot. Should a sample have any of those conditions, the sera will be returned to the parent tube and ejected for manual manipulation. For samples clear of those conditions, they will proceed from AQN to BCC to RSP and finally archived in the Flexible Sample Sorter Module (FSS). The sera will then continue on into the SWA for testing or taken out for Cobas testing. Only for MPA, the racks used cannot be reused until data clean is done by the night staff.

I can't find any good pictures to post so here's the link (http://rochediagnostics.ca/lab/solutions/modular-pap.php)for a clearer understanding with labelled picture. Hope it helps(:

Goh Michelle
0703478H
TG02

5 comments:

  1. hey michelle,

    do u use the same racks to slot in the 'shorter' tubes and the 'taller' tubes? or do u use a different one for each type?

    thanks.

    Natasha :]

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  2. Same type of racks but different racks for different heights. For in house specimens loading into MPA, we use blue racks with a green sticker. So all the shorter tubes in one rack and the taller tubes into another rack. can understand right?

    Michelle(:

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  3. Are all of the 3 machines, Cobas, MPA and SWA capable of doing the same test? If yes, then why is there a need to use 3 machines? What are the differences between each of them?

    Alvin

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  4. What are some of the test performed on these machines? Focus on one of them and explain the clinical significance of the test.

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  5. To Alvin,
    MPA does not run any tests. It just minimize the lab technicians exposure to blood. For our lab, Cobas and SWA does all the common general tests like liver panel, lipid panel etc. For the less common ones like TDM, lactate serum etc, it will be done either by Cobas or SWA.

    Michelle

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