Unit 3

Question 1

What is whole blood comprised of, where is it found

Answer 1

Found in the vessels (circulates the body) (blood transports oxygen, carbon dioxide, nutrients, waste and hormones)

Comprised on RBCs, WBCs, platelets, plasma (proteins, waste products and ion)

Question 2

What is plasma

Answer 2

The fluid portion of blood containing an anticoagulant in which formed elements are removed after centrifuging (unclotted blood)

Contains fibrinogen and other clotting factors and proteins

Normally clear and straw coloured

Question 3

What is serum

Answer 3

The clear, straw coloured liquid portion of blood that does NOT contain fibrinogen or formed elements (clotted blood)

Question 4

What tests must be run determines what about blood collection

Answer 4

Collection site, procedure and equipment

Question 5

True or false
Samples should be collected before any treatments are started

Answer 5

True

Question 6

Why just alcohol be allowed to dry from the skin before blood collection

Answer 6

If any of the alcohol is brought into the syringe while collecting, it can cause hemolysis to RBCs

Question 7

True or false
You must remove the needle when transferring blood from a syringe to a vacutainer

Answer 7

True

Question 8

What are some benefits of vacutainer systems

Answer 8

Reduces artifacts

Prevents the veins from collapsing

Question 9

What is a serum collection tube (red top), what are they used for?

Answer 9

Does NOT contain an anticoagulant

Used to allow blood to clot to remove serum

Used for a large number of biochemical blood test or used for storage and shipment of histology samples, hair samples etc

NOT used for hematology tests

Question 10

What are heparin tubes (green top) what are they used for?

Answer 10

Contain heparin as an anticoagulant (sodium, potassium, lithium or ammonium salt)

Used for biochemistry tests particularly when while blood is needed

Never used for differential blood film analysis

Question 11

What is an EDTA tube? (Purple top) What are they used for

Answer 11

Contains Ethylene diamine tetra acetic acid (powdered or liquid) (sodium or potassium salt)

First choice for hematology tests

Almost consistent preservation of cell volume and morphological features

Must be mixed gently when blood is added (too much EDTA will nullify automated machine analysis)

NOT used for chemistry tests (EDTA and calcium will interfere with tests)

Question 12

What are Oxalate and citrate tubes (blue top)? What are they used for

Answer 12

oxalates available in sodium, potassium, ammonium or lithium salts

Citrates available in sodium or lithium salts (also used for blood transfusions)

Interfere with clotting by binding with calcium

Interfere with chemistry tests

May need to be refrigerated

Question 13

What are sodium fluoride tubes (grey top)? What are they used for

Answer 13

Used for preserving blood glucose in a sample (questionable effectiveness)

Interferes with many enzyme tests

Question 14

What is a sure-sep or serum separator tube? (Red with black or grey mottled top -tiger top)

Answer 14

A variation of a red top tube, does not contain an anticoagulant

Contains a gel in the bottom of the tube to separate the cells from the serum when it is centrifuged (when spun, RBCs go under the gel)

Prevents cells from metabolizing analytes

Question 15

What does the amount of sample collected depend on? How much should you collect gold standard)

Answer 15

Volume required for tests needed

Patient hydration status

Should collect enough to run the test 3 times (allows for technical errors, instrument failure, dilution of sample, etc)

Question 16

How much volume of blood is serum/plasma in a healthy vs dehydrated patient

Answer 16

Healthy: approx 1/2 the volume of whole blood is serum/plasma

Dehydrated: half that ^ (1/4)

Question 17

What does a blood collection tube need to be labelled with

Answer 17

Patient name/identification

Date and time

Sample type

Initials

Question 18

Blood collected for CBC should be analyzed within _ hours of collection. If not possible what should be done?

Answer 18

1 hour of collection

Make a blood smear and refrigerate the tube

Question 19

True or false

Blood smears should not be refrigerated

Answer 19

True

Question 20

What temperature should blood be analyzed at

Answer 20

Room temp

(Remove from fridge 30 min before running a test)

Question 21

Why should you never freeze blood

Answer 21

Causes cells to lyse

Question 22

Using a vacutainer system, what types should be filled first? What about with a needle and syringe?

Answer 22

Vacutainer system: Serum tubes (no anticoagulant) (don’t want to contaminated the red top with anticoagulant from the other tubes)

Needle and syringe: anticoagulant tubes first (reduces risks of clots in anticoagulant tubes)

Question 23

A chemical analysis of the blood is performed to evaluate electrolytes, proteins, enzyme levels and other analytes within the ___ portion of blood, usually on ___

Answer 23

Liquid, usually on serum

Question 24

Why are fasted samples preferred

Answer 24

Glucose, urea, lipase and cholesterol may be affected if the animal has eaten recently

12 hour fasts are required for some tests

Question 25

How long should a serum tube be let to sit in order to clot

Answer 25

20-30 minutes at room temp

Question 26

What are some things that will affect chemistry results

Answer 26

Pathology
Hemolysis
Icterus
Lipemia
Medications
Diet
Improper sample handling/collection

Question 27

Why may hemolysis occur

Answer 27

Aspiration of alcohol
Damp syringe
Small diameter needle
Too much suction
Transferring blood from the syringe through the needle
Rough mixing
Over centrifugation
Freezing

Question 28

How does hemolysis affect results

Answer 28

Cell rupture causes the sample to be artificially dilute due to fluid leakage from the cells

May increase concentrations of some metabolites

Interferes with lipase activity

Alters bilirubin determination

Question 29

Why do patients need to be fasted for 12 hours before blood collection

Answer 29

Inorganic phosphorus levels may be increased after a meal

Glucose, cholesterol and lipids will be increased

Lipemia (increases turbidity if the sample altering results)

Question 30

What are reference ranges (normal ranges)

Answer 30

These are specific to the analyzer and test method being used

Determined based on running samples on multiple “normal” animals

Specific to species (may be impacted by breed and age)