PetriKey

Lab method

Antigen test concept

Detects microbial protein or polysaccharide target

AN-tih-jen test

labantigenimmunoassayrapid-testspecificity

High-yield clue

Antigen test looks for a pathogen component; antibody tests look for host response.

Overview

An immunologic testing concept used to distinguish antigen detection from antibody detection and nucleic-acid detection in coursework.

Classification

  • Immunoassay concept
  • Detection vocabulary

Lab & identification clues

  • Target antigen vocabulary
  • Sensitivity/specificity concepts
  • Rapid-test term recognition

Associations

  • Respiratory virus testing
  • Cryptococcal antigen
  • Giardia/Cryptosporidium antigen terms

Commonly confused with

  • ELISA
  • PCR
  • NAAT

Your notes

Original concept summary for coursework. Sources checked: OpenStax Microbiology 2e and NCBI Bookshelf Medical Microbiology; reviewed 2026-06. Describes vocabulary and interpretation concepts only; not a lab protocol and not for handling specimens or identifying patient isolates.

OpenStax: Microbiology 2e staining, media, and biochemical-test foundationssourceNCBI Bookshelf: Medical Microbiology diagnostic concept foundationssource