Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2021 May 6;13:30. doi: 10.1186/s13099-021-00425-5

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

© The Author(s) 2021

Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

PMC Copyright notice

Fig. 1 — Photographs of representative plaques. a A negative control. b Show the appearance of a small number of plaques; in this case taken from 10% of the buffy coat of 8 ml of blood. c Shows how the plaque numbers are obtained. Using the Stuart Colony Counter, each time a mark is made on the bottom of the petri dish, as the dish is depressed, the count is automatically tabulated. d A plate where the plaque count is 688 plaques, determined using the Stuart colony counter as demonstrated in panel C. e A plate where the number of plaques are “Too Numerous To Count.” In this particular case the inoculum was from 10% of the buffy coat. f 25% of the buffy coat from the same blood sample as shown in “e” was inoculated. In this plate the plaques are so numerous that the entire plate has been “Cleared”. No discrete plaques at all are discernable. Compare this appearance with that of the hazy appearance of the Control plate (Panel “A”) which is the appearance of the M. smegmatis lawn. (see Materials and methods)