ASCP CG Exam (Molecular CG Testing) Verified Answers And Questions 2026

ASCP CG Exam (Molecular CG
Testing)
What is the purpose of post hybridization wash? - CORRECT ANSWER-Remove
unbound probe from the slide.

What is true about slide prep for FISH? - CORRECT ANSWER-Slides should be kept at
room temp conditions.

When analyzing a sample stained with a FISH probe, the technologist notices a high
amount of nonspecific cross hybridization. Which is most likely the cause? - CORRECT
ANSWER-The stringency was way too low.

When using the Applied Imaging system to capture the FISH image, which program
should be chosen to use? - CORRECT ANSWER-Probe.

Which of the following statements is true about directly labeled probes? - CORRECT
ANSWER-Exposure to light should be avoided.

All of the following are advantages of array-CGH except? - CORRECT ANSWER-The
use of metaphase chromosomes.

Which counterstain dye should be used to counterstain cells with Spectrum
Green/Spectrum Red dual color signals? - CORRECT ANSWER-DAPI.

DAPI is a _______ counterstain. - CORRECT ANSWER-Blue.

The process of FISH is used to: - CORRECT ANSWER-Visualize a specific sequence
of DNA with a fluorochrome.

Which is critical to the success of a FISH procedure? - CORRECT ANSWER-
Temperature of the denature solution.

Formamide is used in the FISH procedure for which of the following purposes? -
CORRECT ANSWER-To lower the DNA melting point.


Which of the following regarding test resolution is correct? - CORRECT ANSWER-BAC
array has lower resolution than oligo array.

Which of the following are the QC measurements for array-CGH? - CORRECT
ANSWER-Triplicate clones used, dye swap, and equal amount sample/reference DNA.

, True/False: Array-based CGH is a molecular technique that detects balanced genomic
rearrangements (translocations and insertions ) by comparing test DNA to normal
reference DNA. - CORRECT ANSWER-False.

Which is not an indication of aCGH testing? - CORRECT ANSWER-A mother carries an
inverted 9 found by karyotyping analysis.

What types of specimens can FISH be performed on? - CORRECT ANSWER-
Chromosomes, touch preps, cytospin preps, PETs, smears, disaggregated nuclei,
uncultured amniocytes, and blastomere/blastocyst.

What are painting probes? - CORRECT ANSWER-Probes that hybridize to the unique
sequences which cover the length of an entire chromosome.

Why do we use painting probes? - CORRECT ANSWER-To study marker
chromosomes, translocations, and aneuploidy.

What are alpha-satellite probes? - CORRECT ANSWER-Probes that hybridize to the
repetitive sequences located at the centromeres of chromosomes.

True/False: Alpha-satellite DNA is composed of 171 bp repeats that are polymorphic
from individual to individual. - CORRECT ANSWER-True.

What are beta-satellite probes? - CORRECT ANSWER-Probes that hybridize to 68 bp
repeats located on the short arm of the acrocentrics.

What are classical satellite probes? - CORRECT ANSWER-Proves that hybridize to the
heterochromatic regions of 1, 9, 16, and Y.

What is true about the heterochromatic regions of 1, 9, 16, and Y? - CORRECT
ANSWER-The DNA is highly polymorphic and is composed of numerous tandem
repeats of the AATGG sequence.

What are telomere probes? - CORRECT ANSWER-Probes that hybridize to the terminal
ends of the p and q arms of chromosomes.

What sequence is associated with the telomeres of chromosomes? - CORRECT
ANSWER-TTAGGG.

Which area close to the telomeres has a unique sequence? - CORRECT ANSWER-The
subtelomeric regions.

What are locus specific probes? - CORRECT ANSWER-Probes that hybridize to a
unique sequence or gene.