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