SCYM Cell Cycle & DNA Content Analysis 3

Question 1

Which dedicated software tool uses polynomial and Gaussian modeling algorithms specifically for automated cell cycle and DNA ploidy analysis?

Accepted Answer

ModFit LT

Answer

ModFit LT employs polynomial S-phase fitting combined with Gaussian G1 and G2/M peak modeling to deconvolute overlapping cell cycle compartments and calculate ploidy parameters.

Question 2

What maximum CV for the G0/G1 peak is generally considered acceptable for clinical DNA ploidy analysis by flow cytometry?

Accepted Answer

Less than 5%

Answer

A CV below 5% for the G0/G1 peak is the widely accepted threshold for clinical DNA ploidy analysis, ensuring the G1 and G2/M peaks are sufficiently resolved to detect aneuploid populations.

Question 3

Which antibody marker best helps distinguish tetraploid G1 cells (4N) from true G2/M cells (also 4N) in DNA content analysis?

Accepted Answer

MPM-2 anti-phosphoprotein antibody

Answer

MPM-2 recognizes phosphorylated epitopes present specifically on mitotic proteins during G2 and M phase, allowing discrimination of true G2/M cells from tetraploid G1 cells that share the same 4N DNA content.

Question 4

In clinical oncology, a high S-phase fraction (SPF) detected by DNA content analysis in breast cancer is associated with:

Accepted Answer

More aggressive tumor behavior and worse prognosis

Answer

A high SPF indicates rapid cell proliferation, which correlates with more aggressive tumor biology, higher risk of recurrence, and worse clinical outcomes in breast cancer.

Question 5

Which chemical agent is used to synchronize cells at the G1/S boundary by inhibiting ribonucleotide reductase?

Accepted Answer

Hydroxyurea

Answer

Hydroxyurea inhibits ribonucleotide reductase, depleting the deoxyribonucleotide pool and blocking DNA replication at the G1/S boundary without inducing DNA strand breaks.

(SCYM) Specialist in Cytometry Practice Test

(SCYM) Specialist in Cytometry Practice Test

SCYM Cell Cycle & DNA Content Analysis 3