MOLECULAR DIAGNOSTIC EXAM REVIEW
QUESTIONS WITH ACCURATE SOLUTIONS
2026
▶ Will a mismatch in a MCA raise or lower the Tm?? Answer:lower
because the mismatch creates a weaker bond btwn the DNA strands
▶ Heteroduplex analysis? Answer:mixing sample nucleic acid with
reference nucleic acid, denaturing, reannealing, and analysis on gel or
DHPLC to see if there are heteroduplexes which is where the target strand
and reference strand bind and there is a mismatch. If there is a not a
mismatch then this is a homoduplex and the mutation is not present
▶ high density oligonucleotide arrays? Answer:similar to CGH, however
focuses on single genes instead of whole genome, target is fragmented
with DNase H, target fragments and probes hyb due to short fragment size
if the sequence is not perfect, the oligonucleotide will not bind, use multiple
probes with different fluorescent color
▶ bead array? Answer:uses color-coded fluorescent tagged polystyrene
beads in suspension each bead is coated with distinct probes coordinated
to a gene region , requires flow cytometry, antibody and infectious disease
detection as well as tissue typing, advantage of this assay is that multiple
loci can be tested at once
▶ standard tilling? Answer:design of probes an array such that the
mutation site is always at the 12th position
▶ redundant tilling? Answer:design of probes on an array such that a
predictable mutation is located at different places in the probe sequence on
the 3' end 5' end or the middle
▶ SSP-PCR? Answer:sequence-specific primer PCR, used to detect point
mutations, the primer 3' end falls right on the point mutation nucleotide to
be analyzed, the 3' end must match perfectly to be extended by
QUESTIONS WITH ACCURATE SOLUTIONS
2026
▶ Will a mismatch in a MCA raise or lower the Tm?? Answer:lower
because the mismatch creates a weaker bond btwn the DNA strands
▶ Heteroduplex analysis? Answer:mixing sample nucleic acid with
reference nucleic acid, denaturing, reannealing, and analysis on gel or
DHPLC to see if there are heteroduplexes which is where the target strand
and reference strand bind and there is a mismatch. If there is a not a
mismatch then this is a homoduplex and the mutation is not present
▶ high density oligonucleotide arrays? Answer:similar to CGH, however
focuses on single genes instead of whole genome, target is fragmented
with DNase H, target fragments and probes hyb due to short fragment size
if the sequence is not perfect, the oligonucleotide will not bind, use multiple
probes with different fluorescent color
▶ bead array? Answer:uses color-coded fluorescent tagged polystyrene
beads in suspension each bead is coated with distinct probes coordinated
to a gene region , requires flow cytometry, antibody and infectious disease
detection as well as tissue typing, advantage of this assay is that multiple
loci can be tested at once
▶ standard tilling? Answer:design of probes an array such that the
mutation site is always at the 12th position
▶ redundant tilling? Answer:design of probes on an array such that a
predictable mutation is located at different places in the probe sequence on
the 3' end 5' end or the middle
▶ SSP-PCR? Answer:sequence-specific primer PCR, used to detect point
mutations, the primer 3' end falls right on the point mutation nucleotide to
be analyzed, the 3' end must match perfectly to be extended by
