CLINICAL LAB SCIENEC

CHAPTER 15: MICROBIOLOGY 393
9. Touch the loop to the second quadrant and streak all the way across the third
quadrant, again repeating the process 7 or 8 times
10. Streak the fourth quadrants to produce isolation of bacterial colonies in much the
same manner as was done for the second and third quadrants (Figure 15-4). Sterilize
the inoculating loop or needle by using the incinerator for several seconds, then
place the loop handle into the stand attached to the incinerator. Take care not to
contaminate the loop or needle after sterilizing it following use, as the hot metal may
burn burn the hands or work surface.
11. Differential biochemical disks aid in identification of certain organisms and are
indicated for some cultures. This is done by placing appropriate differentiating
discs on the surface of the inoculated agar plate. These discs contain certain
chemicals that affect the growth of the bacteria and are based on the source of
the culture (throat, etc.) and the suspected species of bacteria. This is done after
streaking the media and before incubating the agar plate.
12. Identify the inoculated media on the lid by using a permanent marker capable of
withstanding the moist heat of an incubator. The identification information may
include a patient’s ID number or name.
13. Replace the lid on the inoculated agar plate and place it upside down in an incubator
set at 36°C–37°C.
FIGURE 15-4 Streaking for isolation of bacterial colonies.
Source: Delmar/Cengage Learning.
Copyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).
Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.