fundamentals of biochem labs

Question 1

why do clinical biochem

Answer 1

diagnosis, screnning
aetiology
monitoring
therapy

Question 2

what kind ofquestions does biochem asses

Answer 2

• metabolic control
• tissue damage
• systems function
• toxins
• genetics

Question 3

whatdoes biochem measure

Answer 3

• metabolits
• enzymes
• hormones
• mcromolecules
• drugs

Question 4

example of developing personalised medicine

Answer 4

herceptin drug for breast cancer

Question 5

what is HER/neu

Answer 5

a gene product

transmembrane prtein tyrosin kinase

Question 6

what does herceptin doe

Answer 6

humanised Ab that blocks receptor

Question 7

advatnagtes of using blood for testing

Answer 7

easy to get hold of
visits all tissues
immediate response

Question 8

disadvanatges of using blood

Answer 8

complex mis
snap shot only
analyte has to be in circulation

Question 9

advantages of using urine

Answer 9

easy to get hold of
reflects rate of production and metabolism for many tissues
indcates time averagedresponses

Question 10

disadvantdes of using urine

Answer 10

short sharp peaks are averaged out

analyte has to go through the kidney and eb water solubl

Question 11

advantages of using urine

Answer 11

easy to get hold of
intimately reflects the GI tract
might reflect fat soluble analytes

Question 12

disadvantages of using faeces

Answer 12

variable mixture
affected by diet
can be altered by bacteria in transit

Question 13

challenges of anaytical biochem

Answer 13

• complex mix of compounds
• presence of many smiliar molecules
• whats the molecular biovariability of the analyte
• mix of water soluble and lipid soluble molecules
• wide vriety of concentrations
• some things come in multiple forms of bound or unbound

Question 14

analytical tools used:

Answer 14

• wet chem, test tubes
• dry film chem
• enzymes
• immunoassay

Question 15

whatare the two types of wet chem

Answer 15

• inorganic using test tubes and detecting colourchanges

- enzymes changes looking fr oxidation or production of something eg ATP production

Question 16

how are enzymes used

Answer 16

analytical reagents to catalyse reactions with moleucular specificity

Question 17

use of Ab in biochm

Answer 17

• immunoprecipitation

- ELISA assay

Question 18

how is immuno-precipitation used?

Answer 18

used to measure quanitities of something

- add Ab to sample and measure how much is recipitated out and this is the amout of the analyte in questions

Question 19

comepetetive immunassay

Answer 19

add known amount of labelled antige to fixed AB

measure how much the label is diluted and howmuch is bound using a curve

Question 20

types of immuno labels

Answer 20

radioisotypes
floursecence
enzymes for amplification
chemilminescecnce

Question 21

hook effect

Answer 21

confouding effect of immunoassays

other Ab and proteins bind and only half the sandwich formd hook in standard curve

Question 22

OSNA

Answer 22

one step nucelic acid amplification
becomng used in hopsitals
lets surgeons known while during surgey if the whole tumour has been remoed
detects for tumor DNA in guardiah lymphnodes

Question 23

the acid test

Answer 23

litmus paper

vegatable pignement into celulose paper

Question 24

colours f litmus paper

Answer 24

blue: alkali
red: acid

Question 25

paper test for cyanide

Answer 25

ferrous hydroxide

Question 26

paper test for arsine

Answer 26

mercuric bromide

Question 27

layer of dry reagent films

Answer 27

TOP
upper slide mouth
spreading layer
reagent laters
support layer
lower slide mount
BOTTOM

Question 28

spreading layer of dry reagent films

Answer 28

fibrous material or membrane that when a drop of dample is added spreads it out laterally
ensures uniform difussion of sample into analytical layers

Question 29

anayltical layers of dry reageent films

Answer 29

thin porous gelatine films with reagents in

fibrous material can also be added to filter blood cells from plasma and to separate reactions

Question 30

why are reflective layers used in the dry films

Answer 30

refelct back as much of the light emmited by the chem reactions
may be a pigment or metal foil

Question 31

role of the surrport later

Answer 31

mechanical foundations of the elements

thin plastic to trasnmit light

Question 32

what are the analytical layers in blood glucosefilm strips

Answer 32

• buffer
  glucose oxidase to generate hydrogen peroxide from glucose and oxygen
  periodiase together with redox indiator to make visible colour reaction

Question 33

how is serum creatinine measured

Answer 33

end ith hydrogen perioxide and this measures with a dye of leuco dye

Question 34

measuring c reactive protein CRP

Answer 34

diagnosis for inflmatory diseases

- Ab to CRB bound to horseradish peroxidase, hydrogen perioxide made and detected with leuco dye

Question 35

measuring T4

Answer 35

Ab to T4 bound to matrix
glucose oxdase converts into hydrogen perioxidae and colour seen
more t4 in sample means more competetion and more enters lower layers and more colour changeseen

Question 36

how are dry reagent chem films quanitified

Answer 36

some are all or nothing, either pos or neg eg urine pregnancy tests
bust some are semiquantitiative including urine analysis strips

Question 37

how does quanitittion through light absorption work

Answer 37

oncentration of pgment of reactio colour measured by the light signal and quantified by beer lamberts law
absoption spectrophotmetery

Question 38

does dry reagant chem use apsoption spectophometry

Answer 38

NO

Question 39

what kind of light photemtry does dry chem use

Answer 39

reflectance photmetry

light from above