Lab Techniques

Question 1

What are reference intervals

Answer 1

The upper and lower limits for 95% of healthy animals

Question 2

What percentage of animals are outliers (with concern to reference intervals)

Answer 2

1/20 (5%)

Question 3

What is the lower reference interval

Answer 3

Mean - 2 Standard Deviations

Question 4

What is the upper reference interval

Answer 4

Mean + 2 Standard Deviations

Question 5

What are some reasons in which reference intervals should be used with caution

Answer 5

Outliers (5%) Exercise anemia in horses Food ingestion in SA

Question 6

How should you interpret lab results?

Answer 6

ERC - Extracting, Rank, Connect Extract: all abnormal value Rank: all abnormal values (below or above RI) to mild, moderate, marked Connect: lab pattern with history and c/s

Question 7

Ways of collecting blood

Answer 7

Whole Serum Plasma

Question 8

Cytology methods

Answer 8

Fluids Biopsies FNAs

Question 9

Urine collection methods

Answer 9

Free catch Cysto Catheterized

Question 10

When should you collect blood from large animals? Why?

Answer 10

Morning - before exercise so splenic contractions dont give innacurate RBC results (may appear higher)

Question 11

When should you collect blood from small animals? Why?

Answer 11

Morning (before meal) - to avoid collection of lipids. Lipids can cause hemolysis

Question 12

What is an iatrogenic cause of hemolysis in blood collection

Answer 12

Needles can cause hemolysis and damage to cell morphology

Question 13

What effect do clots have on blood samples

Answer 13

Artefact: lowers platelet, RBC and WBC counts

Question 14

Which element do anticoagulants in blood tubes bind to

Answer 14

Calcium

Question 15

What effect does excess EDTA or excess blood have on blood sample

Answer 15

Excess EDTA (too little blood in sample): shrinks RBCs —-> iron deficiency

Excess blood (too much in tube): clot formation

Question 16

Which tube preserves cell morphology best? (TQ)

Answer 16

EDTA

Question 17

What are 3 benefits of EDTA tube

Answer 17

Preserves cell morphology best

Interferes least with romanowsky stains

Prevents clot formation in joint fluids

Question 18

T/F - EDTA is best for coagulation tests

Answer 18

False! Forms insoluble complex with Ca

Question 19

Which tube is best for fish

Answer 19

Lithium heparin

Question 20

T/F - EDTA should be frozen (TQ)

Answer 20

F - NEVER (cells will expand)

Question 21

Which tube is best for CBC. Do you separate plasma and cells (TQ)

Answer 21

EDTA - no you dont separate

Question 22

EDTA: in vitro hemolysis causes which artefacts

Answer 22

Lowers RBC Lowers PCV Increases MCHC

Question 23

Which test do you use with lithium heparin (TQ)

Answer 23

Chemisty

Question 24

Which is anticoagulant tube of choice for biochemistry?

Answer 24

Lithium heparin

Question 25

What is the difference between serum and plasma

Answer 25

Serum - no platelets or clotting factors

Question 26

Which is more stable - plasma or serum?

Answer 26

Serum. The fibrinogen in plasma increases degradation

Question 27

Which is blood tube of choice for bile acids? TQ

Answer 27

Plain blood tube

Question 28

Which is blood tube of choice for serology? TQ

Answer 28

Plain blood tube

Question 29

Which is blood tube of choice for glucose and lactate? Why? TQ

Answer 29

Fluoride oxalate. It prevents RBCs from using glucose

Question 30

You run an blood assay using a lithium heparate tube. Your results suggest the patient is hypoglycemic. Do you trust these results?

Answer 30

No - in lithium heparin RBCs stay active and will utilize glucose in blood. If you run glucose assay in lithium heparate tube, there will be an iatrogenic artefact

Question 31

Which is tube of choice for coagulation tests? TQ

Answer 31

Sodium citrate - because it binds poorly with calcium

Question 32

Do you put serum or plasma in sodium citrate tubes

Answer 32

Plasma

Question 33

T/F - chemistry samples can be frozen (are there exceptions)

Answer 33

True - if analysis is \>24h Exception- Ammonia!! Analyze within 60 min `

Question 34

What artefacts are caused by in vitro hemolysis

Answer 34

Increased K+ Increased phosphate Increased AST

Question 35

Should you refridgerate or freeze your biochemistry sample if your analysis is \<24h

Answer 35

Refridgerate

Question 36

What are evidence of contamination in urine samples

Answer 36

Bacteria (rods, cocci) WBCs (neutrophils)

Question 37

What are benefits of cystocentesis? Is it normal to see some blood

Answer 37

No contamination by microbes, epithelial cells May see some blood

Question 38

Containers used for urine specimens

Answer 38

Sterile, chemical free tubes

Question 39

Why do you need to examine urine specimens asap?

Answer 39

Bacterial multiplication may cause cell lysis and casts Causes false positive chemical reactions

Question 40

Which tubes are best for bacterial culture

Answer 40

Sterilin tubes (or plain blood tubes)

Question 41

What should you collect lavage samples in

Answer 41

EDTA tubes Sterilin tubes

Question 42

What do you collect CSF in

Answer 42

EDTA

Question 43

Which 2 samples do you need to analyze in \<1hr

Answer 43

CSF - very low in protein which maintains cell integrity. Cells degrade quickly. Ammonia

Question 44

What can you add to CSF to stabilize the sample

Answer 44

Bovine serum albumin

Question 45

What type of samples are used for touch imprints

Answer 45

Punch biospies Necropsies

Question 46

What should you do if you are sending urgent samples on a Friday evening

Answer 46

Call the lab