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Biology 161 Blood Lab
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In this Lab
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5.
Hematocrit Reading
Measuring Hemoglobin
Blood Differential (White Blood Cells)
Identifying Blood Disorders
Blood Typing (Examples Only)
Hematocrit
Defn. - The percentage of total blood volume occupied
by erythrocytes. Hematocrit increases with
polycythemia and dehydration and decreases with
anemia.
Polycythemia – an abnormally high number of
erythrocytes.
Anemia – reduced oxygen carrying ability in the blood
due to too few erythrocytes or abnormal
hemoglobin.
Hematocrit Reading
Layers
Top The Yellow – plasma collects
at the top
Middle The Buffer Coat - The
White Blood Cells
Bottom The Red – RBC’s Collected
at the bottom of the
hematocrit tube.
Normal Hematocrit Readings
Males – 40 to 50 % (5,200,000 RBC’s / mm3)
Females – 37 to 47% (4,700,000 RBC’s/ mm3)
Hemoglobin
• The basic way to
compare blood by
color on the color
chart.
• Orange indicates
anemia.
• Deep Red indicates
normal hemoglobin.
Normal Hemoglobin Readings
• Males – 13 to 18 g/100ml
• Females - 12 – 16 g/100ml
White Blood Cells (Leukocytes)
White blood cells are grouped in to two major categories,
Granulocytes and Agranulocytes.
Granulocytes – are roughly spherical in shape, they are larger
than RBC’s, have lobed nuclei, and their cytoplasmic granules
stain specific colors with Wright’s Stain.
Agranulocytes – are WBC’s that lack visible cytoplasmic granules.
Their Nuclei are typically spherical or kidney shaped.
WBC’s - Granulocytes
Basophils (0-2%) –
• release heparin and
histamine.
• The granules stain
purple and the deep
purple
• lobed nucleus has
two or three
constrictions.
WBC’s - Granulocytes
Eosinophils (0-4%)
• fight allergies.
• They have a bi-lobed
nucleus
• red cytoplasmic
granules.
WBC’s - Granulocytes
Neutrophils (60-70%) –
• 1st WBC to an infection
• mature neutrophils have
a 4-5 lobed nucleus
• cytoplasmic granules
stain mauve.
WBC’s - Agranulocytes
Monocytes (4-9%) –
• carry out phagocytosis ie.
macrophages.
• These are the largest
White Blood Cells.
• The nucleus is a U-shape
• the cytoplasm is a greyblue color.
WBC’s - Agranulocytes
Lymphocytes (20-25%)
• provide immunity:
• T and B cells.
• These are the smallest
WBC’s.
• The nucleus of these cells
is spherical and takes up
most of the cell.
Differential
Note- when beginning your differential, RBC’s normally
cover the entire field of view.
Differential – is a comparison by numbers of the
numbers and type of white blood cells on a person’s
blood slide. This is used to determine if there is a
diagnostic increase of a certain type of cells. To do a
differential we will sequentially go back a forth
across the blood slide, count 50 WBC’s and double
the number to give us a percentage.
Blood Typing
• Transfusion of the wrong blood type into an
individual can be fatal
• Red Blood Cell Plasma membranes have highly
specific glycoproteins at their external surfaces called
“antigens”
• Presence or absence of each antigen allows each
person’s blood cells to be classified into blood groups
Blood Typing
Antigen –
• from the words antibody generating is a molecule that
sometimes stimulates an immune response
• are highly specific glycoproteins that are at a red blood cells
external surface (surface antigens)
Agglutinogen –
• since the RBC antigens promote agglutination they are called
Agglutinogens
Blood Typing
Antibody – is a protein molecule that is released by a plasma cell
that binds to a specific antigen.
• are proteins found in the blood that are used by the immune
system to identify and neutralize foreign objects
Agglutinin –
• preformed antibodies that act against RBC’s carrying the ABO
antigens
• Found in the plasma
Agglutination
• Involves red blood cells and can be used to identify
RBC surface antigens (with known antibodies) or to
screen for antibodies (with RBCs with known surface
antigens).
• When faced with a different blood type the donor’s
red blood cells are attacked by the recipients plasma
agglutinins
• Clumping of the RBC’s occurs
ABO Blood Groups
• ABO blood groups are based on the presence
or absence of two agglutinogens type A or
type B
• The use of serum containing the plasma
antibodies, agglutinins, is used to cause the
agglutination of the blood and identify type
according to the surface antigens present
Blood Types
AB – has both A and B surface antigens, and has
neither anti-A nor anti-B antibodies in it’s plasma.
• Therefore AB blood types can receive blood from any
blood type but can only donate to another AB blood
type.
B – has B surface antigens, and has anti A antibodies in
it’s plasma
• Therefore B blood types can receive blood from type
B or type O and donate blood to type B or type AB
Blood Types
A – contains A surface antigens and anti – B antibodies
in it’s plasma.
• Therefore A blood types can receive blood from type
A and type O and donate blood to type A and type
AB.
O – has neither type A or type B surface antigens and
has both anti- A and anti- B antibodies in its plasma
• Therefore O blood types can receive blood from type
O and donate blood to type A, B and AB (Universal
donor)
Blood Typing
Rh Factor
• This blood typing system was named due to one Rh
antigen (agglutinogen D) was first isolated in a
Rhesus monkey. It was later found in humans.
• About 85% of Americans are Rh+
• As a rule a person’s Rh and ABO blood types are
reported together for example A+ or B- or O+
Rh Factor
• Anti Rh antibodies are not spontaneously formed in
the blood.
• However if a Rh- person receives Rh+ blood in a
transfusion the immune system will produce anti Rh
antibodies
• After the second transfusion the same agglutination
patterns can be seen
• Hence the problems that occur with Erythroblastosis
fetalis (hemolytic disease of the newborn)
Normal Blood Slide
Erythroblastosis Fetalis
• This may occur when an Rh- mother has her second
Rh+ baby.
• Bleeding from the placenta detaching from the
uterus causes antigens from the Rh+ newborn to
pass into the mother’s blood stream.
• Without treatment the mother will develop anti
Rh antibodies which are then passed to the next
Rh+ baby which destroys the newborns red blood
cells
Erythroblastosis Fetalis
• causes hemolysis of
immature RBC’s
(erythroblasts =
reticulocytes) which
are nucleated RBC’s.
• Note the prickly cells.
The baby suffers from
anemia because the
RBC’s die before they
can carry oxygen.
Leukemia
Leukocytosis (increase in
WBC’s but they are
immature and incapable
of performing immune
function)
• There is a decrease in
the number of RBC’s
and thrombocytes so
there is anemia and
pinpoint bleeding and
bruising.
Infectious Mononucleosis
Commonly called the “kissing disease”
this highly contagious viral disease
often seen in young adults.
• It is caused by the Epstein-Barr virus
and is characterized in the blood by
an increase in the number of
lymphocytes and monocytes
(atypical lymphocytes).
• 50 – 95% of the WBC’s present may
be lymphocytes and monocytes
(normal 35%).
• The WBC count will also increase
from 7,000 to 11,000 per cubic mm
to 20,000 WBC / mm3
Sickle Cell Anemia
Is caused by the abnormal
hemoglobin (HbS) rather than
HbA.
• The cells become sickle in shape
and can’t carry oxygen well
causing anemia.
• They become stuck together and
clog capillaries.
• These events interfere with
oxygen delivery, and during
increased respiration leave the
victim in pain and gasping for air.
Hypochromic Anemia
• Erythrocytes are small
and pale.
• This is caused either as a
secondary response to a
hemorrhagic anemia, or
from an inadequate
intake of iron in the diet.
Midterm Exam 1
• February 28th in EC Fredricks Theatre (5pm –
8pm)
• 21 questions with A an B parts
• 1 minute per slide on power point
• Practice exam to be posted this week
• Urinalysis cups to be given out at exam, bring
full to next lab.