Other Amplification Methods
Molecular Diagnostics
(MDx) Review 560
METHOD EXPLANATION APPLICATIONS
Probe amplification
Ligase chain reaction (LCR)
Strand-displacement
amplification (SDA)
Signal amplification
Branched chain DNA (bDNA)
Hybrid capture assay
Cleavage-based amplification
(Invader technology)
Was used to detect C. trachomatis&
Neisseria gonorrhoeae in clinical
specimens but taken off market.
ID of Legionella pneumophila,
C. trachomatis, N. gonorrhoeae.
Detection of HBV, HCV, CMV; HIV
viral loads.
Detection of HPV.
Detection of cystic fibrosis, factor
V Leiden, HPV.
Pair of probes designed to hybridize to opposite ends of
target DNA. DNA ligase will join pair together if there
is an exact match to target bases, then probe acts as
template for additional replication. Ligation doesn’t
occur if there are any base mismatches.
Isothermal rxn involving amplification of probes/primers.
Probes capture target sequence to solid support. Extender,
preamplifier, & amplifier probes hybridize sequentially.
Final probe is branched & carries signal-generating
enzymes that act on chemiluminescent substrate.
Complexes containing target DNA bind to antibodies on
solid support. Detected by enzyme-labeled antibodies.
Isothermal method that uses primary probe, invader
probe, reporter probe. Enzyme cleavage amplifies
reporter probe bound to DNA target.
