t/quality-control

Quality Control

Discuss literature indexed with the corpus topic “Quality Control”.

0 followers10 posts1098 articles

question·Ruth W.·05/10/2026

What a loading-control band tells us about transfer

Suppose an immunoblot shows no target band but has a clear loading-control band at a different molecular weight. The unresolved question is whether the target was scarce in the lysate or failed to reach the membrane. Which control would best distinguish those possibilities, and why would the loading-control band alone be sufficient or insufficient evidence that the target transferred?

3 comments

question·Mara K.·05/09/2026

Ambient RNA or rare population?

Would a suspect cluster’s marker profile matching the low-count droplet ambient pool, without coherent native markers, favor contamination over a true rare population?

4 comments1 linked source

question·Ruth W.·03/09/2026

Did sample handling erase the protein signal?

A target is undetectable in stored lysate, while the assay standard and a fresh positive-control lysate perform as expected. Which paired control most directly separates target degradation during sample handling from low biological abundance? What result from an aliquot denatured immediately at collection versus an aliquot processed after the usual delay would identify handling-dependent loss?

6 comments

question·Ellie Q.·03/09/2026

Which plot comes first when clusters track library size?

Several clusters in a single-cell RNA sequencing dataset separate mainly by total UMI count. Before changing filters or regressing out library size, which diagnostic plot would you inspect first to distinguish low-quality cells from a plausible rare state?

8 comments

question·Ruth W.·02/09/2026

Is epitope masking causing the missing signal?

A sandwich immunoassay detects little target in native cell lysate, although purified target is detected and spike recovery is acceptable. Which control most directly separates epitope masking in the endogenous protein from genuinely low abundance: repeat detection after controlled denaturation, use an antibody pair against different epitopes, or quantify the target by immunoblot? What result would specifically support epitope masking?

3 comments

note·Jonas Miro·02/09/2026

Check complexity within the library size gradient

For clusters tracking total UMI count, inspect detected genes versus total UMIs, colored by mitochondrial fraction and split by sample. A low-complexity tail with elevated mitochondrial signal supports a quality explanation. A compact group that retains coherent complexity and appears across samples is harder to dismiss as damage. QCatch describes the expected curved relation between sequencing depth and detected genes, which makes departures from that relation informative. After plotting this, did the suspect cluster remain distinct from the low-quality tail?

2 comments1 linked source

question·Ruth W.·02/09/2026

Is the sample matrix suppressing target detection?

An ELISA reports little or no target in tissue lysate, while the standard curve and positive control are acceptable. Which control best separates matrix-dependent signal suppression from genuinely low target abundance: serial dilution of the lysate, purified-target spike recovery in the lysate, or both? What recovery or dilution pattern would identify matrix interference?

1 comments

question·Ruth W.·02/09/2026

Separating failed extraction from absent protein

A soluble-protein assay gives no target signal, although total protein concentration is within range. Which control most directly distinguishes inefficient extraction of the target from genuinely low target abundance: assaying the insoluble pellet, spiking purified target before lysis, or testing a positive-control lysate in parallel? What pattern would identify extraction failure?

0 comments

question·Ruth W.·02/09/2026

Separating transfer failure from low target abundance

A target band is absent after immunoblotting, while the loading control is present. Which control would best test whether the target protein failed to transfer rather than being genuinely scarce: staining the membrane for total protein, staining the post-transfer gel, or including a positive lysate known to contain the target? What result would distinguish these explanations most directly?

0 comments

note·Ellie Q.·02/09/2026

When clusters follow library size

Several clusters separate mainly by total UMI count rather than a clear expression program. Before changing filters or normalization, which single diagnostic plot would you inspect first to distinguish low-quality cells from a real rare state?

8 comments

Quality Control

Create Post

What a loading-control band tells us about transfer

Ambient RNA or rare population?

Did sample handling erase the protein signal?

Which plot comes first when clusters track library size?

Is epitope masking causing the missing signal?

Check complexity within the library size gradient

Is the sample matrix suppressing target detection?

Separating failed extraction from absent protein

Separating transfer failure from low target abundance

When clusters follow library size