Question

answer 16.17. and 18 please

16. Describe the "Type and Screen" and explain why and when it may be used in some Blood Banks? 17. Why may the antibody screening test be substituted for the minor crossmatch? 18. Discuss the specimens required for compatibility testing (including age requirements, anticoagulant requirements, etc.).

Answer 1

Answer 1a)Describe the "type and screen" -

Blood typing - Blood typing is generally are the lab test that basically identifies blood group antigens belonging to the ABO blood group system.The blood have four groups designed A,B,AB,O.the tests are performed on the blood after it has been separated into cells and serum(the yellow liquid left after the blood cells are removed).

Antibodies screening- antibodies screening is a test to detect atypical antibodies in the serum that may or may not form at the time of blood transfusions or pregnancy. The type of screening is done on the person who needs a transfusion of the blood products. An antibody is a protein produced by the lymphocytes that binds to the antigen.

answer1b) why and when used in blood banks-

1)Basically, people must receive blood of the same blood type, otherwise a severe transfusion reaction may occur. Therefore, blood typing and screening are most commonly performed to ensure that a person who needs transfusions will receive blood that matches his or her own, that clinically significant antibodies are identified if present.

2)pregnant mothers, expecting a baby have their blood type to diagnose and prevent the hemolytic disease example erthroblastosis fetalis.the blood of father,mother,child are compared for paternity.

3)in some criminals forensic investigation typing of blood may be used,identifying the suspect.

ABO typing is the first test done on blood when transfusions. A person must received the ABO matched blood because ABO incompatibility are the major cause of the fatal transfusion reaction. Antibodies screening is done to look for the unexpected antibodies to other blood groups, the recipient serum is mixed with the screening reagent red blood cells.

answer2- the antibodies screening test can be substituted for the minor crossmatch-

Crossmatch is the final step in the pretransfusion testing.before blood from the donor and the recipient is cross matched.both the abo and rh type.to begin here with we will take a unit of blood from the donor with same ABO and RH type as the recipient is selected. Serum from the patient is mixed with the red blood cells from the donor.they see,if the clumping occurs ,the blood is not compatible, if clumping does not occurs ,the blood is compatible.

if an unexpected antibody is found in either the patient or donor, the blood bank do the further testing to ensure the blood is compatible.

minor crossmatch compares the donor serum to recipient erthrocystes and checks are performed antibodies in the donor serum that could hemolysis the recipient red cells.it is

answer3)specimens required for the compatibility test-

Age : donors should be between the age of 18 to 65 years.

Hemoglobin or packed cell volume: the hemoglobin should not be less than 12gm/dl .

Anticoagulant solutions: the anticoagulant should be sterile and pyrogen free.one of the following solutions can be used in the indicated volumes .

Citrate phosphate dextrose: 14ml solution is required for 100ml of blood.

Citrate phosphate dextrose adenine: 14ml solution on 100ml blood

100ml sag or any approved additive solution containing saline adenine and glucose is added to packed cells after sepation of plasma for storage. The integral donor tubing of the plastic bags should be filled with anticoagulant blood and sealed.

Temperature: immediately after collection ,the blood should be stored at 4 degree Celsius.

Quantitative storage : the whole blood or components should be issued for transfusion ,till the mandatory tests are completed and reported as non reactive.the untested blood should be there in quantitative storage.till sent for disposal.

Washed red cells

Leucocyte depleted ted blood cells

Frozen red blood cells concentrate

Single donor plasma

Fresh frozen plasma