Clinical Tests for Metabolites and Biomarkers Flashcards Preview

MCM Test 1 > Clinical Tests for Metabolites and Biomarkers > Flashcards

Flashcards in Clinical Tests for Metabolites and Biomarkers Deck (12):
1

what is a biomarker?

a protein or small molecule for which changes correlate with disease states

2

what is a standard curve?

a curve defined using reference samples with known conentrations; can be used to interpolate patient values
out of range when above or below the standard curve

3

what are two types of detection tests?

enzymatic assay and ELISA

4

how do enzymatic assays work?

use synthetic metabolites to detect patient enzymes
OR
use synthesized enzymes to detect patient metabolites

5

what is kcat?

rate constant of second step

6

how does a change in enzyme concentration affect vmax?

more enzymes = higher vmax

7

how does an ELISA work?

use synthesized antibody to detect patient antigen: metabolite or biomarker
OR
use synthesized antigen to detect patient antibody: pathogen exposure or auto-antibody

8

what are advantages to using an ELISA?

antibody-antigen interaction has high affinity, is not easily disrupted, has good specificity
each antibody has 2 identical binding sites for antigen

9

what are sources of a false positive ELISA?

cross reactivity

10

what are sources of a false negative ELISA?

antigen level below detection limit
OR
body hasn't made an antibody yet (2 weeks)

11

what biomarker is the gold standard for AMI detection?

troponin I

12

what time frame is best for troponin detection?

begins to appear after 4 hours post MI , peaks at 24 hours