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Flashcards in fundamentals of biochem labs Deck (39):
1

why do clinical biochem

diagnosis, screnning
aetiology
monitoring
therapy

2

what kind ofquestions does biochem asses

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

3

whatdoes biochem measure

- metabolits
- enzymes
- hormones
- mcromolecules
- drugs

4

example of developing personalised medicine

herceptin drug for breast cancer

5

what is HER/neu

a gene product
transmembrane prtein tyrosin kinase

6

what does herceptin doe

humanised Ab that blocks receptor

7

advatnagtes of using blood for testing

easy to get hold of
visits all tissues
immediate response

8

disadvanatges of using blood

complex mis
snap shot only
analyte has to be in circulation

9

advantages of using urine

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

10

disadvantdes of using urine

short sharp peaks are averaged out
analyte has to go through the kidney and eb water solubl

11

advantages of using urine

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

12

disadvantages of using faeces

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

13

challenges of anaytical biochem

- 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

14

analytical tools used:

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

15

whatare the two types of wet chem

- inorganic using test tubes and detecting colourchanges
- enzymes changes looking fr oxidation or production of something eg ATP production

16

how are enzymes used

analytical reagents to catalyse reactions with moleucular specificity

17

use of Ab in biochm

- immunoprecipitation
- ELISA assay

18

how is immuno-precipitation used?

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

19

comepetetive immunassay

add known amount of labelled antige to fixed AB
measure how much the label is diluted and howmuch is bound using a curve

20

types of immuno labels

radioisotypes
floursecence
enzymes for amplification
chemilminescecnce

21

hook effect

confouding effect of immunoassays
other Ab and proteins bind and only half the sandwich formd hook in standard curve

22

OSNA

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

23

the acid test

litmus paper
vegatable pignement into celulose paper

24

colours f litmus paper

blue: alkali
red: acid

25

paper test for cyanide

ferrous hydroxide

26

paper test for arsine

mercuric bromide

27

layer of dry reagent films

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

28

spreading layer of dry reagent films

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

29

anayltical layers of dry reageent films

thin porous gelatine films with reagents in
fibrous material can also be added to filter blood cells from plasma and to separate reactions

30

why are reflective layers used in the dry films

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

31

role of the surrport later

mechanical foundations of the elements
thin plastic to trasnmit light

32

what are the analytical layers in blood glucosefilm strips

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

33

how is serum creatinine measured

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

34

measuring c reactive protein CRP

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

35

measuring T4

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

36

how are dry reagent chem films quanitified

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

37

how does quanitittion through light absorption work

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

38

does dry reagant chem use apsoption spectophometry

NO

39

what kind of light photemtry does dry chem use

reflectance photmetry
light from above