Sample Types With Pros And Cons

Question 1

Blood Serum (Fluid after blood clotting)

Answer 1

Pros
+ Easy to get
+ Visits virtually all tissues
+ Indicates immediate status of body + responses

Cons
+ Complex mixture
+ Snapshot of the timeframe of when test was taken
+ Analyte has to get into the circulation
+ Natural Rhythms (?)

Question 2

Urine

Answer 2

Pros
+ Very easy to get
+ Reflects rate of production/metabolism from multiple tissues
+ Indicates time averaged response

Cons
+ Matrix of pH + dilution, dependent on previous consumption contents
+ Short, sharp peaks are all averaged out
+ Analyte has to be handled by the Kidney
+ Metabolites need to be water soluble, which analytically is a challenge

Question 3

Poop

Answer 3

Pros
+ Easy to get
+ Intimately reflects GI tract activity
+ Might also reflect fat soluble analyte

Cons
+ Very variable mixture
+ Affected by recent diet
+ Analyte is often altered in transit ie due to microflora metabolism affecting poop contents

Question 4

Cerebrospinal fluid (CSF)

Answer 4

Pros
+ Clean + fairly simple fluid
+ Intimately reflects CNS activities

Cons
+ Invasive + difficult to get
+ Easily contaminated with blood
+ Relevant to a very specific number of diseases

Question 5

Tissue

Answer 5

Pros
+ Precisely located to the biochemical site of defect
+ Can link structure + function

Cons
\+ Hard to get, requires biopsy
\+ Might miss the small defective area within the target tissue
\+ Relevant to small number of diseases
\+ Difficult to express results