Clin Chem Exam1

Front 1

List the 8 steps involved in obtaining a laboratory test

Back 1

1. written or computerized order is placed
2. pt is id'ed, specimen is collected & properly labeled
3. specimen & order are transported to the lab
4. specimen is accessioned in the lab
5.spec. is processed and transported to tech.
6. spec. is analyzed
7. result reviewed and verified by tech.
8. results released to pt's records

Front 2

Compare the 5 major types of samples in terms of their use in clinical chemistry

Back 2

*Whole Blood -- Cells& liquid not separated.
*Serum -- Centrifuged liquid from clotted blood
*Plasma -- Centrifuged liquid from anticoag blood.
Urine -- Random vs. timed (usually 24 hrs)
*Other Fluids– (CSF), Amniotic fluid, saliva etc

Front 3

Serum is:

Back 3

the supernatant obtained if a blood sample is allowed to clot (fibrinogen converts to fibrin) and then centrifuged

Front 4

Plasma is:

Back 4

the clear yellow supernatant obtained by centrifuging a blood sample that has been treated with an anticoagulant to prevent clotting of red cells. (has all proteins + fibrinogen)

Front 5

Anticoagulant is:

Back 5

a substance that suppresses, delays or prevents coagulation of blood by preventing the formation of fibrin. Ex: EDTA

Front 6

Preservative is:

Back 6

a chemical that prevents a change in the concentration of analytes in a sample of blood, urine, or other body fluid.

Front 7

Additive is:

Back 7

a chemical added to a specimen that changes 1+ of its physical/chemical properties

Front 8

red-topped tube:

Back 8

contain no anticoag or preservatives.
used for collecting serum
~20 mins is required to allow blood to clot before centrifuging.
Used for blood bank specimens, some chem

Front 9

Gold & Tiger Topped:

Back 9

contain a gel that forms a physical barrier b/w the serum &cells after centrifugation.
No other additives are present.
Also known as SST (serum separator tube).
Gel barrier may affect some lab tests.
Can be used for most chem analysis.

Front 10

Grey-topped tube

Back 10

*NaF & K+ oxalate, or
Na+ iodoacetate
*Both preservatives stabilize glucose in plasma
*NaF/oxalate inhibits enolase
*Iodoacetate inhibits glucose-3-phosphate dehydrogenase

Front 11

Green-topped tube

Back 11

*Sodium, ammonium, or Li+ salt of heparin
*(amt. of Na+, Li+ or NH4+ is insignificant.)

Front 12

advantage of Heparin:

Back 12

no time is wasted waiting for the specimen to clot
*Heparin inhibits thrombin, so blood does not clot (plasma)

Front 13

Lavender-topped tubes:

Back 13

contain EDTA (Na2, K2 or K3 ) *it chelates divalent cations like calcium, & inhibits coag.
*Produces falsely low Fe, Ca and Mg results and falsely high K results
*Used for heme & some chem

Front 14

Blue-topped tubes:

Back 14

contain sodium citrate, which chelates calcium and inhibits coagulation

The blood:anticoag ratio must be precisely known, since the tubes are used for coag studies

Front 15

Common Pre-analytical error:

Back 15

Pt & sample misidentification is a very common cause of erroneous lab results

Front 16

Diet affecting pre-analytical:

Back 16

Glucose, lipids, electrolytes, phosphorus, hormones etc.

Front 17

Exercise affecting pre-analytical:

Back 17

↑CK, protein, creatinine, lactic acid, uric acid etc
Smoking—Ammonia ,CEA, glucose, GH, Urea etc. (cont.)

Front 18

analytical variable- lipemic

Back 18

turbid sample due to ↑ triglyceride

Front 19

Diurnal variation affecting pre-analytical:

Back 19

Iron, Cortisol and other hormones, Glucose etc.

Front 20

icteric sample affecting analytical:

Back 20

yellow sample due to ↑ bilirubin

Front 21

hemolyzed sample affecting analytical:

Back 21

– red sample due to hemoglobin
-causes ↑ K, enzymes, phosphorus etc and ↓ glucose

Front 22

Energy and wavelength are _____ related to each other

Back 22

inversely.
*v=c/wavelength
*E-hc/wavelength

Front 23

Relationship between wavelength and energy is:

Back 23

E = h<--lamda
E = Energy in Ergs
h = Planck’s constant (6.62 x 10-27 erg seconds)
(lamda)= Frequency of light in cycles per second

Front 24

Frequency of light (v) is ____ proportional to wavelength

Back 24

inversely.
*v = c/lamda
v = Frequency of light in cycles per second
c = Speed of light in vacuum (3 x 1017 nm/sec)
lamda = Wavelength in nm

Front 25

define PHOTOMETRY:

Back 25

Measurement of intensity of --- -light falling on a surface from a source w/o consideration of wavelength

Front 26

define SPECTROPHOTOMETRY:

Back 26

-Measurement of intensity of light at a selected wavelength

*is the most commonly used method in the automated clinical chemistry laboratory.

Front 27

Wavelength of light=

Back 27

distance between identical sites on a consecutive wave.

Front 28

Light=

Back 28

is electromagnetic radiation or photons of energy and it behaves like a wave.

Front 29

Light may also behave as it is composed of discrete energy packets called:

Back 29

photons

Front 30

Visible Spectrum: as it goes to the ____, towards the lower wavelength, has _____ energy

Back 30

left; increasing.
*remember=ROYGBIV.
<--white-----red-->
<--UV------IR--->

Front 31

Visible Spectrum: as it goes to the ____, towards the higher wavelengths, it has ____energy.

Back 31

right; less

Front 32

Wavelength <190 nm include____ and ____. These ____ can penetrate through flesh.

Back 32

x rays; gamma rays; photons

Front 33

Wavelength of 190-390 nm is _____, (can be measured), _______.

Back 33

invisible; ultraviolet light (UV)

Front 34

Wavelength of 390-750 nm is_____ light

Back 34

visible

Front 35

Wavelength >750 nm is _______light.

Back 35

infrared

Front 36

__________occurs when electromagnetic radiation is________ by a substance
(neither reflected nor passed through)

Back 36

absorption; assimilated

Front 37

______occurs when electromagnetic radiation moves _____ a substance

Back 37

transmission; through

Front 38

When light passes through a solution, the molecules in solution _____ ______at their characteristic wavelength.

Back 38

absorb light

Front 39

Light that is not absorbed is ________through the solution

Back 39

transmitted

Front 40

Complimentary colors are transmitted:
R-?
O-?
Y-?

Back 40

red-GREEN
orange-VIOLET
yellow-BLUE

Front 41

Valence electrons-are raised from a ____energy orbital (ground state) to a ____ energy orbital (excited state) by_______ energy of a photon

Back 41

low; higher; absorbing

Front 42

______relates concentration of solute to the absorption of light through its solution

Back 42

% Transmittance

Front 43

____ Law: [conc] of a substance is_____ proportional to the amt of light ABSORBED or ______ proportional to the logarithm of the TRANSMITTED light.

Back 43

Beer's; inversely; directly

Front 44

A= εbc means what

Back 44

*A = Absorbance
*c = concentration in moles/L
*b = length of light path through sol’n in cm (width of cuvet)
*ε = a = proportionality constant in L/mol.cm
(extinction coefficient or molar absorptivity, ε )

Front 45

Absorbance varies with:

Back 45

Concentration
PH
temperature

Front 46

Glucose is a _____ agent in the _____ form

Back 46

reducing; aldehyde (aldehexose)

Front 47

Glucose + ATP
_________→ glucose-6-phosphate + ADP

Back 47

hexokinase

Front 48

β-D-glucose + O2
__________→ D-gluconic acid + H2O

Back 48

glucose oxidase

Front 49

Maltose = glucose + ______

Back 49

glucose

Front 50

Simple sugars that contain only one aldehyde or ketone group and two or more hydroxyl (OH) groups

Back 50

Monosaccharides

Front 51

Three monosaccharides with most biological importance are:

Back 51

D-glucose, D-fructose and D-galactose.

Front 52

Lactose = glucose + ________

Back 52

galactose

Front 53

Sucrose = glucose + _______

Back 53

fructose

Front 54

Most important polysaccharides in nature are _____ in plants and _______ in animals.

Back 54

starch; glycogen

Front 55

Reducing sugar –can reduce another compound at the______ end (reducing end)

Back 55

OH

Front 56

name 5 reducing sugars:

Back 56

Glucose
Galactose
Fructose
Lactose
Maltose

Front 57

Carbohydrates from diet are broken down to __________

Back 57

monosacch's

Front 58

_____ ______, in the mouth, hydrolyzes starch to form dextrins and maltose

Back 58

salivary amylase

Front 59

_____ _____, in the small intestine, converts starch& glycogen to maltose. The enzymes in the intestine hydrolyze maltose, along with any ingested lactose and sucrose to glucose, galactose and fructose.

Back 59

pancreatic amylase

Front 60

Monosacch's are absorbed through the intestinal wall into the blood stream and are transported to the_______

Back 60

LIVER!

Front 61

_____is the only monosaccharide used by the body for energy

Back 61

glucose

Front 62

galactose and fructose are converted to _____ by the _____ enzymes.

Back 62

glucose; liver

Front 63

_______ in liver reacts with ATP in the presence of______to form glucose-6-phosphate.

Back 63

glucose; hexokinase

Front 64

Glycolysis (Embden-Meyerhof pathway)– glucose is converted to _______ or ______
(anaerobic + Kreb’s cycle-->ATP+CO2+H2O)

Back 64

pyruvate or lactate

Front 65

BREAKDOWN of glycogen --->glucose-1-P--->glucose –6-P---> glucose

Back 65

glucogenolysis

Front 66

Formation of glucose from non carbohydrate sources such as amino acids, lactate, or glycerol portion of lipids:

Back 66

glucoNEOgenesis

Front 67

Insulin____blood glucose level.

Back 67

decreases

Front 68

All other glucose related hormones (glucagon, epinephrine, cortisol, growth hormone, somatostatin and thyroxine) ______blood glucose level.

Back 68

increases

Front 69

Insulin is a small peptide secreted in response to ______blood glucose level.

Back 69

elevated

Front 70

3 ketone bodies:

Back 70

acetoacetic acid, butyrl

Front 71

UA's can not measure _____ but can measure 1. ______

Back 71

butyric; acetoacetic acid

Front 72

____ has fibrinogen

Back 72

plasma

Front 73

_____ does not have fibrinogen

Back 73

serum

Front 74

plasma has more____ than serum

Back 74

protein

Front 75

a prolonged tourniquette application causes an increased _____, _____, _____ , ______, & ______

Back 75

ammonia; protein; iron; cholesterol; potassium

Front 76

______ is increased in hemolysis

Back 76

potassium in EDTA

Front 77

what is responsible for milky and turbid appearance of a sample?

Back 77

LIPIDS!

Front 78

sorting of samples is an example of a _____ variable?

Back 78

preanalytical

Front 79

when choosing a wavelength on the spectro- if you have a blood (red) sample, which color's wavelength would you choose to test the blood sample with?

Back 79

its complementary color-green.

Front 80

accuracy-QC chart

Back 80

values between the mean

Front 81

values on QC chart that are close together

Back 81

precision

Front 82

outside of ____ S.D. is not reportable

Back 82

+-2

Front 83

LJ chart: ___is on x- axis

Back 83

TIME

Front 84

y- axis on LJ chart is:

Back 84

QC result

Front 85

outside of 2 SD you have to:

Back 85

fix it! must rerun or make corrective action

Front 86

Bias on LJ chart:

Back 86

all high or all low

Front 87

error of accuracy is _____ error

Back 87

systematic

Front 88

a sudden shift on LJ chart is _____ values on continuounce

Back 88

(4-6) OR higher than 1SD shift. esp going away from the mean

Front 89

a gradual shift is called a _____ on an LJ chart.

Back 89

trend

Front 90

LJ charts at a glance show whether there is a sudden loss of ______

Back 90

precision

Front 91

at least 2 different levels of QC which are _____ & ______

Back 91

abn & normal

Front 92

_____ ____ were made for assessing the info from 2 QC samples per batch

Back 92

Westgard rules

Front 93

1s2

Back 93

result of only 1 QC sample is > 2SD but <3SD from its mean. (95%)

Front 94

the only rule not rejected is

Back 94

1s2

Front 95

1-3s

Back 95

result of only 1 QC sample is >3sd from its mean (99.7%); probably RANDOM error (imprecision)

Front 96

2-2s

Back 96

results of 2QC samples are both 2sd from their mean in SAME direction (both high or both low) (95% CI twice)

Front 97

2s2 is ____ error

Back 97

systematic (bias).

Front 98

R4s

Back 98

result of 2QC samples are both 2sd from their means but in opp. directions (1high and 1low) RANGE

Front 99

westgard rules are _____ to LJ charts

Back 99

superior

Front 100

LJ has a ____ % rejection

Back 100

5%

Front 101

westgard has a _____ % rejection

Back 101

0.3%

Front 102

____ is prefered tube for measuring FPG

Back 102

lithium heparin

Front 103

fasting sample (8-10 hrs) is the best sample for _____

Back 103

FPG

Front 104

reducing agents give a falsey____ result

Back 104

decreased. like ascorbic acid

Front 105

oxidizing agents give a falsey _____ result

Back 105

increased; like bleach

Front 106

hexokinase is the method for:

Back 106

reference method for glucose

Front 107

interference in hexokinase method is by...:

Back 107

EDTA anticoag binds Mg++ by falsely decreasing it

Front 108

other reducing sugars, such as _____ will produce a positive result

Back 108

everything!- galactose, maltose...(EXCEPT sucrose)

Front 109

urinalysis method uses the _____ ______ rxn

Back 109

glucose oxidase

Front 110

the prefered tube for collection of preservation

Back 110

sodium fluoride; if in other tubes must separate first

Front 111

Hb A1c estimates the average blood glucose over______

Back 111

2-3months or ~60days

Front 112

a serum specimen was allowed to stand unseparated from clot at RT for 6 hours...the glucose results will be______

Back 112

falsey decreased

Front 113

glycated hbg are less positively charged than HbA. they elute first.

Back 113

Non-glycosylated hgb binds to the resin and stays in the column.

Front 114

____ hgb does not bind very well to the resin; it flows thru the column

Back 114

glycosylated

Front 115

affinity chromatography method is opposite of the______

Back 115

ion-exchange method

Front 116

luminescence is:

Back 116

giving off light without the production of heat or energy

Front 117

fluorescence is directly prop. to:

Back 117

concentration

Front 118

most common lamp used in fluorometry is:

Back 118

xenon

Front 119

most common light used in spectrophotometry is:

Back 119

tungsten

Front 120

monochromater:

Back 120

pick your wavelength

Front 121

fluorometry is measured at a _____ angle

Back 121

90 degrees

Front 122

fluorometry uses a secondary filter to select for _____ wavelengths

Back 122

longer; lower energy

Front 123

advantages for fluorometry:

Back 123

greater in specificity and sensitivity

Front 124

disadvantages for fluorometry:

Back 124

very sensitive to environment changes- temp, contamination, maintenance, pH changes.

Front 125

what measures chemiluminescence?

Back 125

luminometer

Front 126

chemiluminometer does not need____

Back 126

light source or monochromater

Front 127

cv=

Back 127

sd/x

Front 128

nephalometer: (cloud)

Back 128

uses light scatter at a 90 degree angle; measures small part.

Front 129

turbidimetry:

Back 129

light scatter (other angles) insoluble particles; decrease in amt of light; measures larger part.

Front 130

bichromatic:

Back 130

color due to a colored sample

Front 131

a statistical test for comparing the SD of 2 data sets:

Back 131

F-test

Front 132

compares the x:

Back 132

T-test

Front 133

reflectance:

Back 133

a spectrophotometric technique in which light is reflected from the surface of a rxn and used to measure the amt of the analyte

Front 134

light scatter depends on ____ & _____

Back 134

wavelength and particle size

Front 135

s^2 is___:

Back 135

variance

Front 136

glycolysis: glucose is converted itnto____ or _____

Back 136

pyruvate or lactate