Comparison of acridine orange, methylene blue, and Gram stains for blood cultures.

Journal Article (Journal Article)

Direct microscopic screening of blood cultures by Gram stain or methylene blue stain is time consuming and frequently insensitive. Therefore, we evaluated a fluorescent-staining procedure that uses acridine orange (AO) at pH 3.5 and compared it with the methylene blue and Gram stain procedures. All smears were prepared within 24 h of receiving the culture, fixed with methanol, and examined without the results of the companion smears being known. AO-stained smears were examined with incident-light fluorescence at 600 x magnification and confirmed at 1,500x magnification. All bottles macroscopically positive within 24 h were excluded from the study. Of 2,946 cultures entered into the study, 204 (6.9%) were positive within 3 days. The sensitivity and specificity of AO based on these culture results were 52 and 98%, respectively, compared with 38% sensitivity and 99% specificity by methylene blue and Gram stains. The AO staining procedure is a simple, sensitive, screening technique for the early detection of positive blood cultures.

Full Text

Duke Authors

Cited Authors

  • Mirrett, S; Lauer, BA; Miller, GA; Reller, LB

Published Date

  • April 1982

Published In

Volume / Issue

  • 15 / 4

Start / End Page

  • 562 - 566

PubMed ID

  • 6175656

Pubmed Central ID

  • PMC272144

International Standard Serial Number (ISSN)

  • 0095-1137

Digital Object Identifier (DOI)

  • 10.1128/jcm.15.4.562-566.1982


  • eng

Conference Location

  • United States