LIPIDS LAB

Question 1

preferred sample

Answer 1

serum collected in SST

Question 2

preferred for LPP assays

Answer 2

edta plasma

Question 3

fasting hours required

Answer 3

12-14 hour

Question 4

Turbidity of the chylomicrons can interfere with the
spectrophotometric methods of lipid profile by?

Answer 4

falsely increased result

Question 5

specimen type for total cholesterol and HDL

Answer 5

non-fasting specimen

Question 6

specimen type for TAG and LDL

Answer 6

fasting specimens

Question 7

• can lead to decreased plasma volume in relation to volume of pack RBC
• can interfere with the
  result

Answer 7

hemoconcentration

Question 8

long period storage of
serum/plasma

Answer 8

-70C or lower

Question 9

short-term storage of serum/plasma (up to a month or two)

Answer 9

-20C

Question 10

cholesterol measurement methods

Answer 10

can be chemical or enzymatic

Question 11

fasting requirement for cholesterol measurement?

Answer 11

8-12hours

Question 12

specimen type for cholesterol measurement

Answer 12

fasting or non-fasting specimen

Question 13

chemical methods for measuring cholesterol

Answer 13

• Libermann-Burchardt Rxn
• Salkowski Rxn

Question 14

end product of Libermann-Burchardt Rxn

Answer 14

Cholestadienyl Monosulfonic Acid

Question 15

end color of Libermann-Burchardt Rxn

Answer 15

green

Question 16

color developer mixture of Libermann-Burchardt Rxn

Answer 16

a. glacial acetic acid
b. acetic anhydride
c. concentrated sulfuric acid

Question 17

end product of salkowski rxn

Answer 17

Cholestadienyl Disulfonic Acid

Question 18

end color of salkowski rxn

Answer 18

red

Question 19

general methods for measuring cholesterol

Answer 19

1. one-step method
2. two-step method
3. three-step method
4. four-step method

Question 20

one-step method

Answer 20

colorimetry (Pearson, Stern, and Mac Gavack)

Question 21

two-step method

Answer 21

extraction + colorimetry (Bloors)

Question 22

three-step method

Answer 22

saponification + extraction + colorimetry (Abell-Kendal)

Question 23

four-step method

Answer 23

saponification + extraction + colorimetry + precipitation (Schoenheimer, Sperry, Parekh, and Jung)

Question 24

what are the reagents for step methods?

Answer 24

• Liebermann-Burchardt (colorimetry)
• Petroleum ether (saponification)
• Alcoholic potassium hydroxide
• Digitonin (precipitation)

Question 25

CDC REFERENCE METHOD FOR CHOLESTEROL MEASUREMENT

Answer 25

Gas Chromatography Mass Spectrophotometry (GC-MS)

Question 26

TRADITIONAL REFERENCE METHOD FOR CHOLESTEROL

Answer 26

Abell, Levy and Brodie Method

Question 27

enzymatic methods for measuring cholesterol

Answer 27

cholesterol oxidase rxn

Question 28

interference for enzymatic method of measuring total cholesterol

Answer 28

- ascorbic acid, bilirubin, hgb - ascorbic acid: ↑ascorbic acid ↓ TC - bilirubin: oxidized by H2O2 - hemoglobin: has pseudo-peroxidase activity that diminish H2O2 produced in the cholesterol oxidase rxn

Question 29

- Uses hexane extraction / petroleum ether after hydrolysis with alcoholic KOH followed by reaction with Liebermann-Burchardt color reagent - EC: green

Answer 29

Abell, Levy and Brodie Method

Question 30

gold standard method for cholesterol

Answer 30

ISOTOPE DILUTION MASS SPECTROMETRY

Question 31

fasting hours requirement for TAG measurement

Answer 31

10-12 hours

Question 32

specimen for TAG measurement

Answer 32

either plasma or serum

Question 33

CDC Reference Method for TAG Measurement

Answer 33

- Saponification: alcoholic KOH - Extraction: choloroform - Treatment w/ silicilic acid: to remove phospholipids - EP: pink chromophore

Question 34

interference for TAG measurement

Answer 34

HAB - hemolysis - ascorbic acid - bilirubin

Question 35

methods for measuring TAG

Answer 35

- chemical method - enzyme method

Question 36

chemical methods for measuring TAG

Answer 36

1. colorimetric method - Van Handel and Zilversmith 2. fluorometric method - Hantzsch Condensation

Question 37

Van Handel and Zilversmith (colorimetric)

Answer 37

- TAG + KOH → Glycerol + Fatty Acid - Glycerol + Periodate → Formic Acid + Formaldehyde - Formaldehyde + Chromotropic Acid → Chromogen

Question 38

Hantzsch Condensation (fluorometric)

Answer 38

- TAG + KOH → Fatty Acids + Glycerol - Glycerol + Periodate → Formic acid + Formaldehyde - HCHO + Diethyl acetone + NH3 → Diacetyl Lutidine Compound

Question 39

Involves liberation of fatty acids from cholesterol, from triglycerides and KOH

Answer 39

Hantzsch Condensation

Question 40

enzymatic methods for measuring TAG

Answer 40

- Glycerol Kinase Method

Question 41

Reaction A for Glycerol Kinase Method

Answer 41

- TAG + Lipase → Glycerol + Fatty acid - Glycerol + ATP + Glycerol Kinase → Glycerolphosphate +ADP - ADP + Phosphoenol pyruvate + Pyruvate Kinase → ATP + Pyruvate - Pyruvate + NADH + H ion + Lactate dehydrogenase → Lactate + NAD

Question 42

Reaction B for Glycerol KInase Method

Answer 42

- TAG + Lipase → Glycerol + Fatty Acid - Glycerol + ATP + Glycerol Kinase → GlycerolPO4 + ADP - Glycerol PO4 + NAD + GlycerolPO4dehydrogenase → DihydroxyacetonePO4 + NADH - NADH + Tetrazolium dye + Diaphorase → Formasan + NAD+

Question 43

Conditions where there is increased TAG

Answer 43

- Hypothyroidism - Alcoholism - Nephrotic Syndrome - Hyperlipoproteinemia tyeps I, IIb, III, IV, V - Pancreatitis

Question 44

Conditions where there is decreased TAG HMM... B-aba ng tag

Answer 44

- Hyperthyroidism - Malabsorption syndrome - Malnutrition burns - Brain infection