Turbidometry/Optilite Flashcards
What is turbidimetry?
Turbidimetry measures the cloudiness of a solution
Turbidimetry is the process of measuring the loss of intensity of light transmitted through a sample caused by the scattering effect of insoluble particles.
What is the principle behind the optilite analyser
The amount of light that is transmitted through the solution and subsequently measured is indirectly proportional to the amount of antigen present
How does the optilite work
Optilite measures proteins in patient serum
Patient serum is incubated with highly specific polyclonal sheep antisera
Insoluble complexes are formed between antigen of interest and antisera added
When light is passed through the suspension the complexes formed cause a reduction in the light transmitted through the sample
=> amount of light transmitted is indirectly proportional to the specific protein of interest
What is measured on the optilite?
Immunoglobulins (G, A, M)
Alpha 1 anti-trypsin
Caeruloplasmin
Complement proteins C3 and C4
Haptoglobin
Anti-streptolysin Titre
Beta-2 microglobulin
C-1 complement inhibitor
Write about Ig measurement on the optilite
Measured to investigate immunodeficiencies and monoclonal gammopathy
In MG -> Ig results from optilite are used alongside electrophoretogram to investigate
Write about alpha-1-anti-trypsin measurement
Looking for A1AT deficiency
A1AT inhibits the destructive action of neutrophil enzymes
Deficiency causes liver and respiratory issues
Write about caeruloplasmin measurement
An acute phase protein that is involved in iron metabolism
Low in acute inflammatory conditions
Low in Wilson’s disease
Low in trace metal deficiency
Write about complement protein C3 and C4 measurement
Increased C3 and C4 seen in inflammation
Decreases in C3 and C4 seen in activation of classical complement cascade, immune complex diseases such as SLE and in complement consuming states such as sepsis
C3 might be decreased but C4 normal when the alternative pathway is activated e.g. gram negative sepsis or post-streptococcal glomerulonephritis
Write about haptoglobin measurement
A serum protein that binds free plasma haemoglobin to be recycled
Haptoglobin is reduced in states of intravascular haemolysis e.g. in haemolytic anaemia
Write about anti-streptolysin titre measurement
Antibodies produced post streptococcal infection
Can be used to indicate recent infection
Write about beta-2 microglobulin measurement
Prognostic indicator in multiple myeloma
Prognosis is less favourable the higher the B2M
B2M protein is present in large quantities on B-lymphocytes and is increased in increased cell turnover e.g. B-lymphoproliferative neoplasms
Write about C-1 inhibitor measurement
An essential regulator of the complement system
Deficiency leads to unregulated activation of complement as seen in hereditary angioedema
