Topic summary

Coming back to: Lateral-flow and colorimetric approaches: the specificity problem

Analytics › Home & field testing third-party testing LOD & LOQ documentation quality ELISA Solved

This is a generated summary. It shows the 9 most-liked posts from a topic of 90, in their original order, with the accepted answer included where one exists. It is a reading aid and it will miss nuance — the full topic is the record.

p.novotnyTL2Regular Solution18 Apr 2026#4

m.balogun, post #3: post #2 answers the question as asked. The question underneath it is different. Precision of home tests: most consumer-accessible devices are not precise to the level people want ("is this 99% pure or 97% pure"). They give a yes/no or a rough category, not a quantitative number. Go to post

What physical quantity does the device measure? A colorimetric or lateral-flow method typically responds to a class of chemistry rather than to a specific molecule. It can distinguish "peptide present" from "nothing present" but generally cannot distinguish the intended peptide from a closely related one.

7 likes in reply to #3 3mo

e.steinerTL2 Moderator23 Apr 2026 · edited#7

post #6 is right about the mechanism and I think understates the practical bit.

What you can use home tests for: confirmation that a solution contains peptide (as opposed to being saline alone), rough screening for very different compounds (semaglutide versus totally unrelated compound). What you cannot use them for: precise purity assessment or verification that the identity is correct.

25 likes 3mo

p.krastevTL2 Moderator24 May 2026#29

a.cardoso, post #20: post #19 answers the question as asked. The question underneath it is different. Molecular tests: DNA or RNA tests are not applicable to peptides, which do not contain nucleic acids. Peptide-specific tests rely on protein recognition, not nucleic-acid detection. Go to post

post #28 is right about the mechanism and I think understates the practical bit.

Enzyme assays: if you have an enzyme that reacts specifically with your compound, an enzyme-based assay can work. These are sometimes available commercially but are less common than antibody-based tests.

32 likes in reply to #20 2mo

VThorvaldsenTL3Regular30 May 2026#34

Lateral-flow devices: like a rapid COVID test. They have a reagent strip and produce a colour result. They are quick but not precise and not intended for quantitative work.

31 likes 2mo

t.pereiraTL2 Moderator17 Jun 2026#50

Lundqvist, post #44: Worth separating two things that post #40 runs together. What physical quantity does the device measure? A colorimetric or lateral-flow method typically responds to a class of chemistry rather than to a specific molecule. It can distinguish "peptide present" from "nothing present" but generally cannot distinguish the intended peptide… Go to post

I read post #48 twice before replying, because I had assumed the opposite.

Precision of home tests: most consumer-accessible devices are not precise to the level people want ("is this 99% pure or 97% pure"). They give a yes/no or a rough category, not a quantitative number.

29 likes in reply to #44 1mo

y.rahimiTL2 Moderator26 Jun 2026#58

I disagree with the reply above, and I think the disagreement is substantive rather than terminological.

The distinction being drawn does not survive when you look at the published data for this specific question. I would be glad to be shown wrong on this, because the version I am arguing against is more convenient.

33 likes 1mo

blank_injectionTL2Analytical chemist30 Jun 2026#62

Lateral-flow devices: like a rapid COVID test. They have a reagent strip and produce a colour result. They are quick but not precise and not intended for quantitative work.

31 likes 28d

b.jankowiakTL3Regular12 Jul 2026#74

f.laurent, post #41: Molecular tests: DNA or RNA tests are not applicable to peptides, which do not contain nucleic acids. Peptide-specific tests rely on protein recognition, not nucleic-acid detection. Go to post

Molecular tests: DNA or RNA tests are not applicable to peptides, which do not contain nucleic acids. Peptide-specific tests rely on protein recognition, not nucleic-acid detection.

29 likes in reply to #41 16d

e.steinerTL2 Moderator24 Jul 2026#86

Immunoassay limitations: tests that use antibodies have cross-reactivity limitations. An antibody raised to semaglutide will cross-react to some degree with tirzepatide and other structurally similar compounds. The test result conflates them.

28 likes 4d

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