Chemistry Study Guide Flashcards
What is the purpose of centrifugal for in centrifugal analyzers?
to mix
or to separate serum/plasma from rbc’s
What does a lab worker do if acid gets in an eye?
flush with running water and notify a doctor
What do the etched rings on the top of a pipette mean?
TC?
blow out
to contain
What could cause an elevated SG but normal osmolality?
heavier molecules such as proteins or glucose
What are the normal values for CSF glusoce, protein, appearance and WBC’s?
glucose: 50-80 mg/100mL
protein: 15-45 mg/dL
clear and colorless
WBC: 0-5
Why is CO toxic?
it prevents binding of Hgb to Oxygen
TBIL normal values
0.2-1.0 mg/dL
Conjugated/direct bilirubin normal values
0.0-0.2 mg/dL
Unconjugated/Free bilirubin normal values
0.2-0.8 mg/dL
too much bili to liver
increase in urine/feces
hemolytic anemias
Prehepatic jaundice
problem with liver itself
increase in urine/feces
liver disease
Hepatic jaundice
biliary obstruction
decrease/absence in urine/feces
stones/tumors
Posthepatic jaundice
decreased fecal URO
obstructive jaundice
increased bile pigments
jaundice
interpret oral/GTT values
141 200 mg/dL provisional diabetes
Give cautions for bilirubin specimen
protect from light
run STAT
no hemolysis
What enzyme tests cannot be preserved by freezing?
LD - lactate dehydrogenase
What is the cause of postprandial lipemia?
chylomicrons
How does the electrophoresis pattern of plasma differ from that of serum?
sharp fibrinogen peak in plasma
What is the order of migration of proteins on electrophoresis at pH 8.6?
alb, A1, A2, beta, gamma
fast to slow
What is the principle enzyme in salive?
amylase
The IG’s migrate with what protein on electrophoresis at pH8.6?
gamma globulin
How do oral contraceptives affect total T4 and TBG in competitive binding?
increase in both
Creatinine is the breakdown product of what substance?
creatine
What tests are affected by hemolysis?
ACP, ALP, ALT, AST, BIL, CBC, CK, LD, aPTT, PT
What is the normal bicarbonate to dissolved CO2 ratio?
20:1
What is the anticoagulant of choice for blood gas analysis?
heparin
How is serum globulin determined?
TP - albumin
What is the predominant form of thyroid hormone in the circulation?
T4 thyroxine
How is bloody CSF handled in the chemistry lab?
spin; analyze fluid; comment presence of blood
What is the unique value of enzymes as reagents?
specificity
What are the major intracellular and extracellular anions and cations?
in anion: phosphate
in cation: potassium
ex anion: chloride
ex cation: sodium
What is the normal pH of blood?
7.35-7.45
Differentiate a transudate from an exudate.
T: clear, no clots, SG 1.015
What protein is a contributing factor in edema formation?
albumin
How is the blood glucose level affected is the serum if left sitting on the clot for several hours?
decrease by 10% per hour
What is the most accurate pipette for measuring a 1 mL volume?
Oswald-Folin volumetric
What type of fast does the patient undergo for lipid studies?
12 hour
concentration
C1V1 = C2V2
same for normality
N1V1 = N2V2
creatinine clearance
(UcrV)/(PcrT)
T in minutes
BSA ave 1.73
square root of ((height*weight)/3131)
Normality
N = grams/GEW/L
GEW = GMW/total positive valence of ions in compound
Molarity
M = grams/GMW/L
GMW = add molar masses of each element; M is mol/L
Beer’s Law
Cu = Au/As*Cs
Anion gap
(Na + K) - (Cl + HCO3)
NA - (Cl + HCO3)
Kjeldahl protein technique principle
conversion of nitrogen into ammonium; reference method for total protein determination
Biuret method principle
directly proportional to the number of peptide bonds present; specifically reacts with at least 2 peptide bonds or more; tripeptides or larger
Iron binding capacity principle
used to estimate the transferrin level in the serum. By measuring the amount of iron that can potentially bind to the circulating transferrin the latent or unsaturated iron-binding capacity (UIBC). If UIBC is added to serum iron concentration, the TIBC may be obtained.
Osmolality principle
freezing point depression
CrCl/GFR principle
CrCl tests GFR based on assumption that all creatinine passes into the urine; GFR = volume of plasma filtered by the glomerulus per unit of time; GFR = V/t
Bilirubin test principle
Bilirubin pigments in serum or plasma are reacted with a diazo reagent (sulfanilic acid in HCl and sodium nitrite), resulting in a purple product azobilirubin.
The product azobilirubin can be measure spectrophotometrically.
Nephelometer principle
measurement of light is directly proportional to the number of particles in solution
Fluorometer principle
measurement of light excited by a UV light source
Sweat chloride principle
uses pilocarpine through an electric current into the skin
oral GTT principle
detects abnormal glucose metabolism
IF
require for B12 absorption
Jaffe reaction
determines creatinine levels
3 hour GTT
test for gestational diabetes
borderline fasting blood sugar pts
+/- 2 S.D.
includes 95.5% values
What is a hollow cathode lamp used for?
atomic absorption
pheochromocytoma
abnormal adrenal medulla which causes increased VMA, norepinephrine, and epinephrine
5HIAA
increased in cancers involving the entero chromofins of GI tract
Berthelot reaction
hydrolysis of Urea
Reagent used for prostatice acid phosphatase
L tartrate
Reagent used for BUN
diacetyl monoxime
Reagent used for URO
p aminobenzaldehyde
Urinary 17-ketosteroids
increased in adrenal cortex
duodenal fluid testing
diagnose pancreas disease
LDL
indicates CHD
AFP
alpha feta protein: hepatoma
LD
increased in MI
CK
increased 1st in MI
For what is acid phophatase used?
rape
CK isoenzymes
CKMB(heart) increased in MI
CKMM muscle
CKBB brain
uric acid
increased in gout
renal disease
What does the sweat chloride test diagnose?
CF
What does SGOT(AST) indicate
increased in MI, viral hep, skeletal muscle disease
Importance of ionized calcium
low in tetany
Importance of amylase
increased in pancreatic diagnosis
Patients with an increase catabolism of purines most likely have an increased serum concentration of what substance?
uric acid
How would the urine volume of a patient with diabetes insipidus be effected upon administrations of ADH?
decreased
The serum protein electrophoresis pattern in MM shows what abnormality?
spike in gamma globulin region
HDL
40-75 mg/dL
LDL
50-130 mg/dL
Trig
60-150 mg/dL
Chol
140-200 mg/dL
What substance in the intestine is required for the absorption of vitamin B12?
IF
List 3 enzymes whose clinical significance is related to the detection of a MI?
AST
CK
LD
Importance of iron binding capacity
measures transferrin
bilirubin and diazotized sulfanilic acid produces?
azobilirubin
pCO2 measures?
pH
