Hello everyone. Hope all of you are enjoying your SIP, even if you are separated from your friends. For the past 5 weeks, I have been attached to several sections in the clinical laboratory.

1st week: Hematology
2nd week: Hematology
3rd week: Blood Banking
4th week: Order entry and Urinalysis
5th week: Clinical Chemistry

For this post, I am going to talk about the Hematology section. There are several tests that are done in this section. Examples would be Full Blood Count (FBC), Erythrocytes Sedimentation Rate (ESR), Retic count and Malaria test.

Full Blood Count (FBC)

For patient’s samples that are requested to undergo FBC, bloods are to be collected in an EDTA tube. This is to prevent the blood from clotting, as it can produce inaccurate results. To check for any clots that may have occurred, we just use a normal applicator stick. If there is even a small clot, the clot will stick to the applicator stick. If a clot is detected, we will reject the sample and a new sample is requested. At the same time, we will check if the sample is sufficient to be run. If it is less than 1.5ml, the sample will also be rejected. After making sure that there is no clot, the sample will be spun for mixing for about 5 minutes. After that, we will arrange the tubes in a rack before putting it in the machine to be run. The machine, Sysmex XE-2100, will do the FBC and the results will be uploaded to the LIS. If the machine detects some abnormalities in the blood, it will ‘trigger’ another machine which will produce a blood slide for further observation by the medical technologist. This machine, Sysmex SP-1000i, is solely responsible for making blood smearing and staining. So, after the samples have been run through the first machine, the rack will automatically be directed to the 2nd machine. Only the samples that are required to produce a slide will be aspirate out by the machine.

XE-ALPHAN ( Sysmex XE-2100 & SP-100i)

Retrieve from: http://www.sysmex-ap.com/default.asp?pageid=110

After all the tubes have undergone both machines, the results will then have to be validated by the medical technologist. For those samples that have slides being processed, the medical technologists will have to observe the slide under the microscope to view any abnormalities before validating. Abnormalities include increase or decrease in the number of the different type of WBCs, presence of any reactive lymphocytes, etc. If there are abnormalities, a manual differential count is done and the results will be keyed into the LIS.

In scenario where there is not enough blood for the machine to make a slide, a manual smearing and staining is required. So, a blood smear is done manually on a glass slide using another glass slide as a slider. After that, a manual stain will be done where the slide is covered with Wright stain and buffer pH7.2 for 10 minutes. It is then washed using distilled water and left to dry for another 10 minutes. It is then ready for observation. Another alternative for staining is to use the Sysmex SP-1000i under its manual mode where the slide will be put inside the machine manually before staining is carried out.


Retic count

Another test that is carried out in this section is the Retic count. This is to find out the number of retics or reticulocytes present in the blood. Retics are immature red blood cells (RBCs) that have not matured yet. It takes generally one day for the retics to mature and become fully mature RBCs.

To perform this test, a single drop of patient’s blood is mixed with a drop of the retic stain. The retic stain used is actually methyl blue stain. It is then incubated for 15 minutes at 37°C. After that, it will then be manually smeared to a glass slide. The slide is then observed under the microscope where the number of retics is taken note. A retic can be differentiated from mature RBCs by the presence of dark blue granules in its cytoplasm.

Reticulocytes

Retrieve from: http://sg.wrs.yahoo.com/_ylt=A0S0zvgOt4lI0WgBfn4u4gt./SIG=11qi13bn9/EXP=1217071246/**http:/www.umm.edu/imagepages/1491.htm

Thus, a manual count will be carried out where the number or retic is being track down while counting 1000 red cells. The number of retics is reported as a percentage of the total red cells. The normal range of retics for a healthy individual is 0.5%-2%. If the percentage is lower, it indicates that the bone marrow is not producing a normal number of RBCs. It may be due to several reasons like lack of folic acid, iron or vitamin B12 in the diet. To confirm, further tests are needed to diagnose the specific cause. If the percentage is higher, it means that the bone marrow is producing more red cells in response to a blood loss or treatment of anemia.



Differential count

Besides doing the test required, I also learnt how to do a differential count using a DC counter. Before doing the test, I have to know how to differentiate the different types of WBCs like lymphocytes, neutrophils, basophils, monocyte and eosinophils.

Neutrophil
Retrieved from: http://sg.wrs.yahoo.com/_ylt=A0S0zu1YvYlIdBsA.iou4gt./SIG=129lakjtm/EXP=1217072856/**http:/www.technion.ac.il/~mdcourse/274203/lect9.html

Lymphocyte

Retrieved from: http://sg.wrs.yahoo.com/_ylt=A0S0zu5uvolI6fMAStEu4gt./SIG=126nhnksc/EXP=1217073134/**http:/www.niagaracc.suny.edu/val/lymphocytes.html

Basophil

Retrieved from: http://sg.wrs.yahoo.com/_ylt=A0S0zu6hvolI__MA.JIu4gt./SIG=11ue3sbaf/EXP=1217073185/**http:/www.carlalbert.edu/dwann/tissue.htm

Monocyte

Retrieved from: http://sg.wrs.yahoo.com/_ylt=A0S0zvnZvolIg2YBZyMu4gt./SIG=12l6hhp65/EXP=1217073241/**http:/www.montgomerycollege.edu/~wolexik/205_histology__page.htm

Eosinophil

Retrieved from: http://sg.wrs.yahoo.com/_ylt=A0S0zvj.volIwmgBc4wu4gt./SIG=12fm7tkp7/EXP=1217073278/**http:/cellbio.utmb.edu/microanatomy/blood/Question_1bl.htm

It is advisable to start counting the cells when the RBCs are just ‘touching’ each other and not stacked together. This makes the counting easier and more accurate. When the number of WBCs has reached 100 cells, the counter will sound a ring as an indicator. The numbers of cells for each type of WBCs are recorded as a percentage. Any increase or decrease of each type may indicate different illnesses or disease the patient is suffering. Further tests is needed to confirm the diagnosis.

With this, i hope all of you have learnt something from my attachment. Till next time friends..

Take care and don't forget to enjoy yourself!! =D

Name: Nur Sofieyana Bte M.D Ismaeil

Class: TG02