November 18, 2018

Hong Kong PhD Fellowship Scheme by RGC:

Hong Kong PhD Fellowship Scheme for International Students/Scholars: The Hong Kong Research Grants Council (RGC) announces the Hong Kong PhD Fellowship program for International students to study/research in Hong Kong


PhD at Aarhus University: 30 Fully-funded PhD fellowships

Aarhus University and the Graduate School of Health invite applications for enrolment and fully financed PhD fellowships. Both the fully financed PhD fellowships and the research training supplements are allocated in relation to the drawn up strategic criteria:
  • Early recruitment of talents
  • Mobility
  • Interdisciplinary co-operation and networking
  • Co-operation with the business community, university colleges and other external partners in municipalities and regions
Number of fellowships: 30 fully financed PhD fellowships (divided between integrated and ordinary PhD fellowships)
  • A number of Research training supplements (DKK 550,000)
  • The fellowships will be offered during all 4 application rounds (February, May, September and November).
  • For a 3-year PhD study programme applicant must have completed a relevant Master’s degree.
  • The Master’s study has to be equivalent to a Danish Master’s degree of 120 ECTS.
  • The application and all mandatory attachments, including the project description (in English).
  • Project description (5 pages)
  • Master’s degree diploma and transcripts of records
  • Curriculum Vitae
  • Motivation letter and competences
  • Initial PhD plan
  • Recommendation letter from main supervisor
  • Documentation of language skills
  • Agreement for industrial PhD study
  • Plan for combined PhD with clinical work or other
  • Apply online
—————Quick Overview————-
OrganizationAarhus University
Fellowship LevelDoctoral
Subject areasAll disciplines
Fellowship amountFully funded
EligibilityOpen to all nationalities
Deadline19 November 2018


June 8, 2013

Coombs Test : Types, Principle, Procedure and Interpretation

The Coomb’s test (also known as Antiglobulin Test or AGT) refers to two clinical blood tests used in immunohematology which are done to find certain antibodies that cause autoimmune haemolysis of red blood cells (erythrocytes). The two types of Coombs tests are:
  • Direct Coombs test
  • Indirect Coombs test

Principle of Coombs Test

In certain diseases or conditions, an individual’s blood may contain IgG antibodies that can specifically bind to antigens on the red blood cell (RBC) surface membrane. Red cells coated with complement or IgG antibodies do not agglutinate directly when centrifuged. These cells are said to be sensitized with IgG or complement. In order for agglutination to occur an additional antibody, which reacts with the Fc portion of the IgG antibody, or with the C3b or C3d component of complement, must be added to the system. Because antibodies are gamma globulins, an antibody to gamma globulin can form bridges between red cells sensitized with antibody and cause them to agglutinate

Direct Coombs Test

The direct Coombs test (also known as the direct antiglobulin test or DAT) is used to detect if antibodies or complement system factors have bound to RBC surface antigens in vivo. A blood sample is taken and the RBCs are washed and then incubated with antihuman globulin. If this produces agglutination of RBCs, the direct Coombs test is positive, a visual indication that antibodies are bound to the surface of red blood cells.


  1. Prepare 5% cell saline suspension of the cells to be tested.
  2. Label 3 tubes as TPC and NC.
  3. In the tube labeled as T (Test), take 2 drops of 5% saline cell suspension to be tested.
  4. In the test tube labeled as PC (Positive control), take 1 drop of anti D sera and 1 drop of Rh +ve pooled cells.
  5. In the test tube labeled as NC (Negative control), take 1 drop of normal saline and one drop of Rh +ve pooled cells.
  6. Add 2 drops of Anti human globulin to each of the tubes.
  7. Mix well and centrifuge for 1 minute at 1500 rpm.
  8. Resuspend the cells by gentle agigation and examine macroscopically and microscopically for agglutination.

Indirect Coombs Test

The indirect Coombs test (also known as the indirect antiglobulin test or IAT) is used to detect in-vitro antibody-antigen reactions. It is used to detect very low concentrations of antibodies present in a patient’s plasma/serum prior to a blood transfusion. In antenatal care, this test is used to screen pregnant women for antibodies that may cause hemolytic disease of the newborn. The IAT can also be used for compatibility testing, antibody identification, RBC phenotyping, and titration studies.


  1. Label 3 tubes as TPC and NC.
  2. In the tube labeled as T (Test), take 2 drops of test serum.
  3. In the test tube labeled as PC (Positive control), take 1 drop of anti D serum.
  4. In the test tube labeled as NC (Negative control), take 1 drop of normal saline.
  5. Add one drop of 5% cell saline suspension of pooled O Rh +ve cells in each tubes.
  6. Incubate all the tubes at 37°C for 1 hour.
  7. Wash the cells 3 times with normal saline.
  8. Add 2 drops of Anti Human Globulin to each tube.
  9. Keep for 5 minutes and centrifuge at 1500 rpm for 1 minute.
  10. Resuspend the cells and examine macroscopically as well as microscopically for agglutination.


False positive reactions can also occurred when performing this test.  These would not be detected by the use of Coombs Control Check Cells.  Reasons for a false positive reaction could be the following:
  • Using improper sample (clotted cells instead of EDTA for Direct Antiglobulin Test, DAT)
  • Spontaneous agglutination (cells heavily coated with IgM)
  • Non-specific agglutination ("sticky cells")
  • Subject own blood group O Positive (may irreversibly binds to O Pos cells)
All of these reactions would be the result of cells appearing to agglutinate, or actually  agglutinating.  Using a clotted tube for the DAT may allow complement to become activated in the test tube since calcium ions are free to be part of the complement cascade.


False-negative reactions can occur when antigen-antibody reactions have occurred but WASHING IS INADEQUATE and free antibody remains when the anti-human globulin is added.
  • Anti-human globulin (Coombs) antibody prefers to react first with free antibody and then with antibody-coated cells
  • If the free antibody has already reacted with the anti-human globulin, no free Coombs serum to react with Coombs Control Check Cells (CCC)
False negatives that are detected by negative Coombs control cells includes
  • inadequate cell washing
  • delay in adding antiglobulin reagent after the washing step
  • presence of small fibrin clots among the cells
  • inactive, or forgotten, antiglobulin reagent

February 15, 2013

Cross-Matching : Types, Purpose, Principle, Procedure and Interpretation

Cross Matching is a procedure performed prior to a blood transfusion to determine whether donor blood is compatible (or incompatible) with recipient blood. Compatibility is determined through matching of different blood group systems, the most important of which are the ABO and Rh system, and/or by directly testing for the presence of antibodies against a sample of donor tissues or blood.

Cross-matching will detect incompatibilities between the donor and recipient that will not be evident on blood typing. There are two types of cross-matches: Major cross-match and Minor cross-match.
The major crossmatch involves testing the patient’s serum with donor cells to determine whether the patient has an antibody which may cause a hemolytic transfusion reaction or decreased cell survival of donor cells. This is the most important cross-match.
The minor crossmatch involves testing the patients cells with donor plasma to determine whether there is an antibody in the donor’s plasma directed against an antigen on the patient’s cells.


  1. Prepare donor and recipient blood samples:
    For Major crossmatch : Donor’s red cell and recipient serum or plasma
    For Minor crossmatch : Recipient red cells and donor’s serum or plasma
  2. Prepare 3 – 5% cell suspensions of red cells.
  3. Major Crossmatch:
    Label a test tube. Add two drops of the patient serum and one drop of the appropriate donor cell suspension.
  4. Minor Crossmatch:
    Label a test tube. Add two drops of the appropriate donor serum and one drop of the patient cell suspension.
  5. Mix the tubes and incubate at 37°C for about 45 minutes.
  6. Add two drops of AHG (Antihuman globulin) and mix well.
  7. Centrifuge for 1 minute at 1500 rpm
  8. Read macroscopically and microscopically and record the results
The mixture of erythrocytes and serum are observed for hemolysis or microscopically for agglutination. Any evidence of hemolysis/agglutination indicates an incompatible cross-match. Negative results are taken to indicate compatibility.


The tourniquet test can be used to evaluate a patient's tendency to form petechiae due to defects in platelets and/or capillaries. The presence of increased venous pressure in a patient with thrombocytopenia or capillary fragility will increase the capillary pressure and result in petechiae.

(1) Mark a circle on the forearm. This is often 1 inch (2.5 cm) in diameter but some use a larger circle.
(2) Mark any pre-existing skin lesions.
(3) Inflate a sphyngmomanometer about the upper arm to a pressure midway between the systolic and diastolic blood pressures.
(4) Leave the cuff inflated for several minutes, then deflate it. The time of pressure application varies, and may range from 5, 10 or 15 minutes.
(5) The patient should not be left unattended during the test. If a large number of petechiae appear, then the test may need to be terminated early.
(6) Wait a few minutes to allow all petechiae to appear. Count the number of petechiae within the test area.
• Most patients will form no or rare petechiae.
• The cutoff for a positive test varies on a number of factors, such as the desired sensitivity and specificity, the duration that pressure is applied, and the size of the test area.
• Some use >= 5 petechiae after a 5 minutes application period, while others use >= 10 petechiae for a 15 minute application period.

• The test has significant variability, with a large number of variables that are hard to control. The test may be useless if done incorrectly.
• Different areas of the arm may show different number of petechiae. If only 1 area is examined then the fragility may be over or underestimated. It is probably reasonable to count several areas and average the number.
• An arm can only be used every 1 or 2 weeks.