Blood Bank Review (Pink top)

 

Blood Group Antigens 

Blood group is determined by antigens and antibodies in the blood. Blood group antigens are sugars attached to the surface of red blood cell.   

ABO ANTIBODIES 

Antibodies are blood proteins produced by the immune system in response to foreign substance in the body.   

Blood group 

Antigen(s) on RBCS 

Antibodies present in the serum 

Genotype(s) 

A 

 

 

Anti-B 

AA OR AO 

 

B 

 

B 

Anti-A 

BB or BO 

 

AB 

 

A and B 

None 

AB 

0 

 

None 

Anti-A and Anti-B 

00 

 Summary  

 Routine Blood bank tests 

A pink tube is used for routine ABO, Rh  and antibody screen test to ensure that compatible units are transfused. Incompatible blood can cause hemolytic transfusion reaction or death. 

1.  ABO, Rh typing is done to determine your blood type.

ABO grouping or typing can be performed in two ways; 

a. Forward type: Anti A, Anti-B and Anti-D reagents are used in forward grouping to detect A, B, and D antigens present in the blood.

b. Reverse type: Reagent A1 and B cells are used in reverse grouping to detect specific ABO antibodies present in the blood.

2. Antibody screening detects presence of specific alloantibodies or autoantibodies to RBC antigens. 

If an antibody is detected, extended crossmatch is performed to provide donor compatible blood. If no antibody is detected, an immediate crossmatch is performed.

3. Antibody identification is performed if the antibody screen result is positive.

4. Crossmatch is used to determine compatibility of donor’s RBCs with recipient’s blood.

a. Immediate spin crossmatch; If current or past antibody screening is negative

b. Full or extended crossmatch; if current or past antibody screen is positive

ABO Blood tying  

 

ABO  

ANTI A 

Forward typing 

ANTI B 

Forward typing 

ANTI D 

Forward typing 

Rh Control 

Forward typing 

A1 CELL 

Reverse  typing 

B CELL 

Reverse  typing 

BLOOD TYPE 

 

4+ 

0 

4+ 

0 

0 

4+ 

A POS 

 

4+ 

0 

0 

0 

0 

4+ 

A NEG 

 

0 

4+ 

4+ 

0 

4+ 

0 

B POS 

 

0 

4+ 

0 

0 

4+ 

0 

B NEG 

Universal  

recipient 

4+ 

4+ 

4+ 

0 

0 

0 

AB POS  

 

4+ 

4+ 

0 

0 

0 

0 

AB NEG 

Universal donor 

0 

0 

4+ 

0 

4+ 

4+ 

O POS 

 

 ABO blood group system is the only blood group system in which an individual have antibodies to antigens they lack without any prior exposure to red blood cell through transfusion or pregnancy.

For Blood Group A Positive; agglutination with anti-A, anti-D and B cells will be observed. 

For Blood Group A Negative; agglutination with anti-A, and B cells will be observed. No agglutination with 

anti D 

For Blood Group AB Negative; agglutination with anti-A, and anti- B will be observed. No agglutination with anti D, A cells and B cells in reverse typing 

For Blood Group O Negative; agglutination with A1 and B cells will be observed. No agglutination with anti A, B and D in forward typing. 

  Grading Reactions

Agglutination from 4+ to 1+;  indicates presence of an antigen or antibody  

Negative reaction means absence of an antigen or antibody 

 Rh Blood Group System  

Of the five antigens only D testing is required. Rh test is used to identify Rhesus factor of blood.  The term “Rh positive” indicates the presence of D antigen on red blood cells while Rh-negatives indicates the absence of D antigen on red blood cells.  

If negative, individual is D negative 

If positive, individual is D positive  

 

 

Hematology Review (Lavender Tube)

MCV(fL) = Hematocrit (%) X 10 / RBC 

 Reference range; 80-100fL 

 MCH (pg) = Hgb X 100 / RBC count  

 Reference range: 26-34pg 

 MCHC (g/dL) = Hgb X 10 / Hematocrit (%) 

Reference range: 32-37g/dL  

Hgb= Hemoglobin

Causes of anemias (MCV) 

Microcytic anemias can be due to Iron deficiency, thalassemia, anemia of chronic disease, sideroblastic anemia and lead poisoning 

Macrocytic anemias can be due to Folate and Vitamin B12 deficiency


 

MCV 

MCHC 

<80fl  (Microcytic anemia) 

<32g/dL (Hypochromic)  

>100fl  (Macrocytic anemia) 

 

Coagulation Review (Blue Top)

 Prothrombin time (PT) and activated partial thromboplastin Time (aPTT) tests are used to evaluate the ability to appropriately form blood clots.  

A blue collection tube containing 3.2% sodium citrate anticoagulant is used for coagulation testing. 

Routine Lab Tests  

1. Activated Partial Thromboplastin Time (aPTT) is used to monitor patients on unfractionated heparin therapy. 

2. Prothrombin Time (PT) is used to monitor warfarin or Coumadin therapy.

3. D-dimer; used to rule out blood clots

Urinalysis Review

 

 

Urine Composition

Water and inorganic compounds.

Urine organic substances:

a. Urea (50%), creatinine and uric acid.

b. Organic substances: vitamins, hormones, protein, and glucose.

c. Urine inorganic substances: chloride, sodium, and potassium, magnesium, calcium, ammonium, sulfate, and phosphate. Chloride has the highest concentration followed by sodium and potassium.

 

Color

 

Yellow color of urine is derived from urochrome.

Urine Volume

Dependent on body’s state of hydration; normal range of urine output 800-2000 mL/24 hr.

Specific Gravity(S.G)

Normal random urine ranges from 1.003 to 1.030

Isosthenuric urine: 1.010 (fixed S.G )

pH  of urine

4.5 to 8.0

Creatinine clearance formula:

C (mL/min) =  U X V   X  1.73 m2

                                        SA

Cells

High power field (hpf)

Low power field (lpf)

Confirmation test

0-2 RBCs (hpf),

0-5 WBCs (hpf),

0-2 hyaline casts (Ipf)

Acetest (Ketones), Icotest (Bilirubin), Sulfosalicylic acid precipitation (Protein)

Clinical Chemistry Tumor Markers Review

α 1 Fetoprotein (AFP)

Increased level; Neural tube defects, spina bifida, and fetal distress

Decreased levels associated with down syndrome

 

Carcinoembryonic antigen (CEA)

Colorectal cancer

 

Human chorionic gonadotropin (Beta-hCG)

Choriocarcinoma

Ovarian tumors

 

CA15-3

Detects breast cancer recurrence

CA125  

Ovarian cancer

CA19-9

 

Gallbladder, pancreatic, colorectal, and gastric carcinomas

Microbiology Gram Positive Cocci Bacteria

Gram staining is a technique used to differentiate between two groups of bacteria based on their different cell wall constituents.  Gram positive bacteria will stain violet due to the presence of a thick layer of peptidoglycan in their cell walls while gram negative bacteria stains red. 

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