Gel card technology ppt nc

Gel card technology

1. Gel Card Technology Guide – Dr Y. R. Gotekar By – Dr Nainshi Bhatt

2. Tests Done in blood bank ABO forward and reverse grouping Cross match Direct Coomb’s Test Indirect Coomb’s test DU Test

3. INTRODUCTION :- Dr. Yves Lapierre of Lyon, France, invented gel card technology. He investigated gelatin, acrylamide gel, and glass beads. As he searched for a way to trap red blood cell (RBC) agglutinates during standardized sedimentation and centrifugation. Gel particles provided the ideal material for trapping the agglutinates. And this discovery led to a patented process i.e. the basis of the gel-based tests.

4. HISTORY :- The gel test was developed in Europe by Dr Yves Lapierre at DiaMed AG ( Murten , Switzerland). Dr. Lapierre is the Director of the Multiple Sclerosis Clinic at the Montreal Neurological Hospital. He is an Associate Professor of Neurology and Neurosurgery at McGill University

5. What is Gel Technology -Gel Technology is an innovative approach to red cell serology that is made to minimize problems associated with conventional techniques of blood grouping. - It also addresses issues of standardization and documentation with unmatched sensitivity, specificity, and efficiency.

6. Instruments used in gel Technology

7. Incubator Centrifuge

8. Gel card - A plastic card with microtube is used instead of a TT. - Gel card measures approx 5x7cm - Consists of 6 or 8 columns.

9. MICROTUBE Prin c ip l e Reaction Cha m ber Add Reactants Seru m /p l as m a/ red cells Gel and Reagent

10. Microtube The reaction chamber is where RBCs may be sensitized (antigen-antibody binding) during incubation. The column of each microtube contains dextran-acrylamide gel particles suspended in a diluent with reagents added, if applicable.

11. Microtube The shape and length of the column provides a large surface area for prolonged contact of the RBCs with the gel particles during centrifugation. Microtubes filled with gel containing anti- IgG are used for compatibility testing, antibody detection, and antibody identification

12. Various types of cards Various Gel Cvards Rh-Subgroups Single Antigen Single Antigen Single Antigen

13. Various types of cards

14. GEL The gel particles make up 75% of the gel-liquid mixture that is preloaded by the manufacturer into each microtube . The gel particles :- - Porous - Serve as a reaction medium and filter, sieving the RBC agglutinates according to size during centrifugation

15. PRINCIPLE -: Haemagglutination test is based on -: Controlled centrifugation of RBCs through a dextran acrylamide gel that contains predispensed reagents. Each microtube is composed of -: - An upper (reaction) chamber that is wider than the tube itself, designed to allow prior incubation of test serum and RBCs. - Narrow portion referred to as column. Serum and cell reaction takes place in a microtube

16. PRINCIPLE -: Sephadex gel matrix acts as a sieve. Large aggutinates remain on or near the top of gel interface. Smaller agglutinates pass partway through gel , depending on size. Unagglutinated cells pass to base of microtube to form a button. Cells are always added prior to the serum so that serum does not comes in contact with the gel- This eliminates the wash phase as in conventional technique.

17. Procedure Measured volume of Rbc’s and serum or plasma Dispensed into the reaction chamber If appropriate, the card is incubated and centrifuged

18. Agglutination Reactions :- Grading

19. Interpretation of the test :- 1+ Aggl . red cell in lower half of gel col. 2+ RBC’s agglutinates throughout the column 3+ Aggltuated rbc’s in upper half 4+ Solid band of red cells at top of gel Negative

20. Mixed-Field reaction :- - The reaction is characterized by a layer of agglutinated RBCs at the top of the column And a pellet of unagglutinated cells at the bottom of the microtube .

21. Mixed-Field reaction :- False-positive mixed-field reactions :- - When incompletely clotted serum is used in the CAT test. - Fibrin strands in such serum may trap unagglutinated RBCs, forming a thin line at the top of the column. - Other unagglutinated cells pass through the column during centrifugation and travel to the bottom of the microtube .

22. APPLICATIONS :- ID-MTS and DG Gel8 are currently cleared by the FDA in the United States for -: - ABO forward and reverse grouping, - Rh typing, - DAT, - Antibody screen, - Antibody identification, - Antibody titration, - Antigen typing, - Compatibility testing.

23. The process of identifying an individual’s bld. grp. Involves testing of red cells with known antisera (FORWARD TYPING) and plasma with known group red cells (BACK/REVERSE TYPING) Forward and reverse typing

24. Forward and reverse typing : Reagents required - ID DiaClon ABO/D + Reverse typing cards containing monoclonal anti- A, anti- B & anti- D suspended in the gel. The tube labeled “ Ctl ” is the negative control. Two tubes with “neutral” gel serve for reverse grouping with A1 and B cells. ID – Diluent 2: modified LISS for red cell suspension. Test cell reagents: ID DiaCell A1, B, O (0.8 ± 0.1% suspension), ready to use.

25. Forward and reverse typing 50 µl Dia c ell A1 50 µl Dia c ell B 50 µl P at i ent Serum 50 µl P at i ent Serum 10 – 12.5µl Patients RBC suspension 5%

26. Forward and reverse typing Incubate the card at room temp. for 10 minutes Centrifuge the card for 10 minutes.

27. Gel Card Procedure Crossmatch ICT DU DCT Major Minor Cell Wash 3 Time Donor Cell Patient Cell O Cells EDTA Sample Cell EDTA Sample Cell Use Sediment Packed Cell 10 µl 10 µl 10 µl 10 µl 10 µl Diluent - 2.0 1 ml 1 ml 1 ml 1 ml 1 ml 0.8 % Red Cell Preparation In 45° Angle 50 µl 50 µl 50 µl 50 µl 50 µl In 90° Angle Patient Serum 25µl Donor Serum 25 µl Patient serum 25 µl Anti-D 25 µl Incubate at 37° C 15 min. 15 min. 15 min. 15 min. Centrifuge 1 cycle 10 min. 10 min. 10 min. 10 min. 10 min.

28. Major Cross Match

29. Patient’s RBC suspension Add 50 µl of above soln. Results DIRECT COOMB’S TEST

30. O cell sus p e n si o n Add 50 µl of above soln. Results Add 25µl of patient serum Centrifuge Incubate INDIRECT COOMB’S TEST

31. Particle Gel ImmunoAssay (PAGIA) Gel Technology now adopted with use of inert polymer particles for detection of: Syphilis Paroxysmal Nocturnal Haemoglobinuria Leishmaniasis Sickle Hb Screening

32. Advantages :- Improved sensitivity and specificity, Easy to use, simple to read No wash phase in IAT Minimal training required . Reliable, reproducible results Easy storage and long shelf life of reagents. Easy disposal of biodegradable cards Widest range of reagents and instrumentation

33. Advantages Compared with traditional tube technology the gel-based tests provide :- - A more stable endpoint - More reproducible results -Eliminating the variability associated with the physical resuspension of RBC buttons after centrifugation and the subjectivity in interpretating hemagglutination reactions.

34. Disadvantags :- Special centrifuge to accommodate the microtubes cards. Special incubators to incubate the microtube cards. Pipette to dispose 25ul of serum. Expensive.

35. Thank you