SCYM Data Analysis 3

Question 1

In dimensionality reduction analysis of high-dimensional cytometry data, what does t-SNE primarily preserve?

Accepted Answer

Local neighborhood relationships between similar cells

Answer

t-SNE (t-distributed Stochastic Neighbor Embedding) preserves local neighborhood structure, placing similar cells near each other while global distances between clusters are not preserved.

Question 2

During cytometry data analysis, 'doublet discrimination' is performed primarily using which parameter combination?

Accepted Answer

FSC-A vs FSC-H or SSC-A vs SSC-H pulse geometry plots

Answer

Doublet discrimination uses pulse area (A) vs. pulse height (H) plots because doublets have proportionally higher area than height compared to singlets of the same size.

Question 3

Which UMAP parameter most controls the balance between preserving local versus global data structure?

Accepted Answer

n_neighbors

Answer

The n_neighbors parameter in UMAP determines how many neighboring points are considered during embedding, with higher values preserving more global structure and lower values emphasizing local clusters.

Question 4

When performing cluster analysis of cytometry data using FlowSOM, what does the meta-clustering step accomplish?

Accepted Answer

Groups similar SOM nodes into biologically meaningful metaclusters

Answer

FlowSOM meta-clustering aggregates individual SOM nodes into larger metaclusters, reducing the hundreds of nodes into a manageable number of biologically interpretable populations.

Question 5

In the context of cytometry data, what is 'arcsinh transformation' most commonly used for?

Accepted Answer

Compressing high-intensity values while expanding low-intensity values for better visualization

Answer

Arcsinh transformation compresses the high end of the dynamic range while expanding detail in the low-signal region, making it ideal for cytometry data with a wide range of intensities.

(SCYM) Specialist in Cytometry Practice Test

(SCYM) Specialist in Cytometry Practice Test

SCYM Data Analysis 3