Other Testing Procedures

Question 1

Principle of nephelometry testing

Answer 1

Soluble complexes that are formed are detected by light scatter, the amount formed is a function of antigen and antibody concentrations, the antibody concentration is kept constant causing the number of formed complexes to vary in direct proportion to the antigen concentration

Question 2

Transferritin saturation percentage

Answer 2

Serum iron concentration (ug/dL) x 100%

Transferrin concentration (mg/dL) x 1.4

Question 3

Haptoglobin measurement

Answer 3

Binds to hemoglobin irreversibly and functions to transport intravascular free hemoglobin to its degradation site in the reticuloendothelial system It is an aid in the diagnosis of hemolytic disease is related to the formation of hemoglobin-haptoglobin complexes and kidney disease

Question 4

CRP

Answer 4

Synthesized by the liver in response to infection or inflammation, production is stimulated by cytokines particularly IL – 6, IL – 1, and tumor necrosis factor Once in tissue it undergoes calcium dependent binding to substances present on bacteria, parasites, and fungi, and then has the ability to activate complement to the classic pathway as well as modulate the function of phagocytic cells CRP has a half-life of 4 to 9 hours

Question 5

PCR

Answer 5

Low levels of specific DNA sequences are amplified using oliginucleotides or primers (small portions of a single DNA strand) and enzymes

Question 6

Gen-Probe

Answer 6

The transport solutions release the rRNA targets and protect them from degradation. A capture probe is short chain of nucleotides with a complementary sequence to the target area of the DNA strand

Question 7

OraQuick

Answer 7

• Waived tests
• Follow manufacturer’s directions
• Sensitivity and specificity of kits determines appropriateness of retesting
• Also, methodology in: Pregnancy testing, Drug of Abuse screening

Question 8

Turbidimetry

Answer 8

A technique for determining the concentration of particles in a solution based on the change in absorbance caused by the scattering of light that occurs when an incident beam is passed through the solution

Question 9

Nephelometry

Answer 9

A technique for determining the concentration of particles in a solution by measuring the light scattered at a particular angle from the incident beam as it passes through the solution

Question 10

In situ hybridization

Answer 10

Binding of a nucleic acid probe to target DNA located in intact cells

Question 11

DNA microarray

Answer 11

A collection of microscopic DNA spots attached to a solid surface, used to measure the expression levels of large numbers of genes simultaneously or to genotype multiple regions of a genome

Question 12

Ligase chain reaction (LCR)

Answer 12

A means of increasing signal probes through the use of an enzyme called a ligase, which joins two pairs of probes only after they have bound to a complementary target sequence

Question 13

AntiStreptolysin O Titer (ASO Titer)

Answer 13

• Involves dilution of patient serum, to which a measured amount of streptolysin O reagent is added.
• Allowed to combine during an incubation period after which reagent red blood cells are added as an indicator.
• If enough antibody is present, the streptolysin O is neutralized and no hemolysis occurs.
• The titer is reported as the reciprocal of the highest dilution demonstrating no hemolysis.