Fundamentals Of Clinical Flashcards
What does clinical biochemistry involve
The biochemical investigation of bodily fluids such as blood, urine and CSF
What is diagnosis
Classical medical processes
What is aetiology
What is the underlying defect:
How does it lead to the pathology
Treatment strategy
What is a cobas ISE module
A very specific method which uses potentiometric measurement to determine the concentration of sodium, potassium and chloride
What does ISE stand for
Ion selective electrode
What sample types are used in cobas ISE module
Serum, plasma, urine and fluids
How long does a ISE test last
30 seconds
What is the ISE module deticated to
Electrolyte measurement
What can cause low sodium
- heart failure
- head injury
- medications, diuretics
What can cause high sodium
- inadequate water intake
- diabetes insipidus
- water loss
What can cause low potassium
- inadequate nutrition
- vomiting/ diarrhoea
- medication, diuretics
What cause cause high potassium
- spurious
- kidney dysfunction
- Addison’s disease
What are limitations to the cobas ISE module
Can sometimes produce erroneous results if the patient has higher than normal levels of proteins and or lipids
What does a Roche c702 modules measure
General chemistry assays such as urea, creatine, LFTS, calcium, magnesium etc
What samples does a Roche c702 use
Serum, plasma, urine, CSF, stool samples and fluids
How long does the Roche c702 test take
About 10 minutes
What technology does a Roche c702 use
Photometric technology to measure analytes
How do photometric assays work
Organic and inorganic compounds in the solution are measured by determining the absorbance of wavelengths of light
What are some analyte examples that are measured using the Roche c702
Creatine, bilirubin, glucose and magnesium
What are some limitations of the Roche c702
Limitations tend to be based around interferants which cause changes in wavelength
What are serum indices
Serum indices are measurements that are performed on every sample that is analysed on the chemistry module
What is a Roche e801 modules
An immunoassay unit
What are immunoassays
Bioanalytical methods in which the quantitation of an analyte depends on the reaction of an antigen and an antibody
How long do e801 tests take
9-32 minutes
What technology do e801 modules do
Electrochemiluminescence (ECL) technology
What are the two types of immunoassays
Sandwich
Competitive
What is a sandwich immunoassay
They use 2 antibodies to bind to different sites on the analyte of interest.
What is a competitive immunoassay
They use one antibody for smaller analytes
What are limitations to the e801 modules
Very high levels of analyte can result in the Hooke effect in sandwich assays.
Antibody production is expensive.
What is osmolality
A measurement of the concentration of dissolved particles within a solution
What is hyponatraemia
Low serum sodium concentration
What is hypernatraemia
High serum sodium concentration
What is an osmometer instrument
An instrument in the laboratory that is a small bench top instrument which works by the principle of freezing point depression
What is the principle of freezing point depression
The freezing point of a liquid is lower when another substance is dissolved in it
Why is sweat chloride analysed
Measurements of chloride in sweat is used to diagnose cystic fibrosis as they have higher levels
What is used to collect the sweat
A specialised device called a macro duct sweat collector
What are limitations of sweat chloride analysis
It’s manual.
Can be difficult to gain sweat from a newborn.
What is a XL spectrophotometer used for
To run an assay known as a CSF xanthochromia
What is xanthochromia
The yellow discolouration or cerebrospinal fluid
What are some limitations to a spectrophotometer
Required specialist training.
Sample needs protecting from light.
The test is not valid until 12 hours after the event.
