Clin Path Lecture 1 (Course Introduction & Proper Sample Storage and Submission)

hematology

What term describes the study of blood?

cytology

What term describes the study of cells, exfoliative or in suspension?

whole blood

_____ _____ represents an unspun, non-clotted sample, +/- anticoagulant; commonly used with point-of-care handheld analyzers in urgent care, anesthetic monitoring, or field settings and for CBCs.

plasma

_____ is the fluid fraction of whole blood obtained from an anticoagulated sample; it is commonly used for benchtop biochemical testing (chemistry).

serum

_____ is the fluid fraction of whole blood obtained from a clotted sample (loss of clotting factors); it is commonly used for benchtop biochemical testing (chemistry) and is sometimes required.

True

T/F: Using small needles to collect a blood sample can cause hemolysis.

hemolysis

Traumatic venipuncture may introduce _____ and/or artificially reduce platelet counts.

EDTA

You should fill purple tops last if possible in order to avoid _____ contamination of samples intended for biochemistry.

true

T/F: You should avoid plunging the syringe when filling collection tubes in order to avoid the excess pressure causing hemolysis.

72 hours

CBC samples should not be centrifuged or frozen. However, if they are refrigerated and brought back to room temp., they are generally acceptable within how many hours?

1. blue
2. green
3. purple

Which 3 color tubes are anticoagulant tubes?

red and white

What 2 color tubes are considered plain?

EDTA

Which anticoagulant does the purple top have?

citrate

Which anticoagulant does the blue top have?

heparin

Which anticoagulant does the green top have?

purple

Which anticoagulant tube is used for CBC? It contains K+ and Na+ EDTA variants; prevents coagulation by chelating calcium; gentler on cells.

green

Which anticoagulant tube is used for plasma biochemistry? It inhibits coagulation by preventing antithrombin.

blue

Which anticoagulant tube is used for coagulation testing? It reversibly prevents coagulation by weakly chelating calcium.

red

Which plain tube is used for serum biochemistry? Clotting time prior to centrifugation depends on species.

white

Which plain tube is used for miscellaneous sample storage?

phenobarbital

Some tests such as _____ measurement, are falsely decreased from fluid fraction contact with the gel separator of tiger top tubes. The gel binds with this bloodwork value which causes the decreased serum concentrations.

tiger tops

Which tubes are serum separator tubes? They contain a gel with intermediate density between cells and serum or plasma. Upon centrifugation, the fluid fraction will be separated from the cell fraction, preventing leeching of certain analytes into the cell fraction.

60 minutes

How long should you let the red top tubes clot for?

30 minutes

How long should you let the gold top tubes clot for?

2

You should centrifuge the red top tubes before _____ hours after clotting.

red

Hemolysis results in free hemoglobin and subsequent _____ discoloration of plasma/serum; may be in vitro or in vivo intravascular hemolysis.

lactescent

Lipemia results in a _____ appearance of plasma/serum; commonly observed in post-prandial samples and why small animal patients should ideally be fasted for blood draw.

bilirubin

Icterus represents elevated _____ and yellow discoloration of plasma/serum; uses species specific rubrics, as large animal plasma and serum naturally have a moderately yellow appearance.

true

T/F: Significant changes to plasma and serum appearance may interfere with CBC and/or clinical chemistry measurements.

1. HCT
2. PCV
3. RBC

In a CBC serum/plasma, in vitro hemolysis falsely decreases what 3 things?

Mean Corpuscular Hemoglobin Concentration (MCHC)

In a CBC serum/plasma, hemolysis falsely increases what value?

MCV

In a CBC serum/plasma, hemolysis does not affect what value?

platelets, leukocytes

With a lipemic CBC serum/plasma sample, large lipid aggregates may be falsely counted as _____ (plural), which increases PLT, or potentially _____ (plural), which increases WBCs.

1. ALT
2. LDH
3. magnesium
4. phosphorus
5. potassium

Hemolysis of a chemistry serum/plasma sample my cause spectrophotometric interference and inhibition of chemical reactions. It can increase what 5 intra-RBC analytes?

creatine kinase

Hemolysis of a chemistry serum/plasma sample my cause a minimal to mild increase in _____ _____ enzymatic activity.

beta globulin

With electrophoresis, severe hemolysis can cause _____ _____ spikes.

increase

A lipemic CBC serum/plasma sample may falsely [increase/decrease] refractometric protein.

hemoglobin

A lipemic CBC serum/plasma sample may falsely increase _____ and subsequently MCHC.

hemolysis

Lipemia also promotes in vitro _____.

refrigeration

With lipemic samples, what can be done to precipitate out the lipid, allowing collection of less lipemic serum/plasma?

no affect

What is the affect of icterus on CBC serum/plasma samples?

biuret total protein and creatinine

Marked to severe icterus/hyperbilirubinemia of chemistry serum/plasma samples may falsely decrease what 2 things?

fibrinogen

Serum = plasma - _____

Platelets and WBCs

The buffy coat is made up of what?