1 - proper sample storage and submission

Question 1

what is whole blood blood sample

Answer 1

an unspun, non-clotted sample. +/- anticoagulant. commonly used for CBCs

Question 2

what is a plasma blood sample

Answer 2

plasma is the fluid fraction of whole blood obtained from an anticoagulated sample. Add anticoagulant then spin the blood down/ let it sit = fluid on top

• Blood without the cells just the fluid

Question 3

what is a serum blood sample

Answer 3

serum is the fluid fraction of whole blood obtained from a clotted sample (loss of clotting factors).

• serum = plasma - fibrinogen (the clotting factor)

Question 4

what is good sample storage

Answer 4

-plasma and serum should be stored properly if not being immediately used
- samples should be stored in the fridge and shipped on ice
- frozen for long term storage
- CBC samples should not be centrifuged or frozen. it is best to run ASAP or fridge for up to 72hrs

Question 5

Explain EDTA purple top tube

Answer 5

EDTA anticoagulant - prevent coagulation by chelating calcium, gentle on cells
- used for CBCs

Question 5

what are some common poor blood collection techniques

Answer 5

• Traumatic venipuncture = hemolysis or reduced platelet counts
• transfer into tubes too slow = blood will clot in syringe
• EDTA contamination if purple top is filled first
• plunging syringe when filling tubes causes increased pressure = hemolysis
• ensure proper volume of blood for anticoagulant

Question 6

what happens when blood sits in the tube

Answer 6

it starts clotting immediately

Question 7

explain heparin Green top tube

Answer 7

inhibits coagulation by potentiating antithrombin
- used for plasma (biochemistry)

Question 8

explain citrate blue top

Answer 8

citrate = anticoagulant
reversibly prevents coagulation by weakly chelating ca
- used for coagulation testing

Question 9

explain red top and white top tubes

Answer 9

Has no additives used for species dependent clotting time prior to centrifugation
- used for serum
white top - misc used for storage sample

Question 10

explain tiger top tubes

Answer 10

Serum separator tubes
- contains gel w/ intermediate density btwn cells and serum or plasma
- upon centfugation the fluid fraction will be separated from the cell fraction, prevention leaching of certain analytes into the cell fraction.

**some tests like phenobarb levels are falsely decreased from fluid fraction contact with the gel separator

Question 11

hemolysis in plasma/serum appearance changes

Answer 11

hemolysis results in free hemoglobin and subsequent red discoloration, may be in vitro or in vivo intravascular hemolysis

Question 12

lipemia in plasma/serum appearance changes

Answer 12

results in a lactescent apperance, commonly observed in post-prandial samples and why sm animal pts should be fasted for blood draws

Question 13

icterus in plasma/serum appearance changes

Answer 13

icterus represents elevated bilirubin and yellow discoloration, uses species specific rubrics. Lg animal plasma and serum naturally have a moderately yellow appearance

Question 14

How can hemolysis plasma and serum appearance interfere with CBC results

Answer 14

• in vitro hemolysis falsely decrease PVC, Hct and RBC counts
• MCHC will be falsely elevated (HBG proportionally higher than Hct or PCV)
• Ghost erythrocytes form intravascular hemolysis may be falsely counted as platelets = increased platelet counts
• refractometric protein becomes difficult to read

Question 15

how can hemolysis plasma and serum appearance interfere with chemistry results

Answer 15

• increase in intra- RBC analytes. Like potassium in horses, camelids and jap dogs. also phosphorus, ALT, LDH and Mg
• can cause a minimal to mild increase in creatine kinase (CK) enzymatic activity

Question 16

how can hemolysis plasma/serum appearance interfere with electrophoresis results

Answer 16

sever hemolysis can cause beta globulin spikes

Question 17

How can lipemia plasma/serum appearance interfere with CBC results

Answer 17

• falsely increased HGB and subsequently MCHC
• Lg lipid aggregated may be falsely counted as platelets and increase PLT or potentially leukocytes increased WBC
• falsely increased refractometric proteins

Question 18

How can lipemia plasma/serum appearance interfere with chemistry results

Answer 18

• spectrophotometric interference
• proportional decrease in Na and Cl, slight decrease in K

Question 19

what does lipemia promote in
blood samples

Answer 19

In vitro hemolysis
- samples can be refrigerated to precipitate out the liquid allowing collection of less lipemic serum/plasma

Question 20

how does icterus plasma/serum samples interfere with CBC and chemistry samples

Answer 20

CBC : little to no effect

Chemistry: marked to severe hyperbilirubinemia falsely decreased biuret, total protein and creatinine