MacConkey’s agar lab worksheet
Lab 10 – How does McConkey agar select for bacteria and differentiate between bacteria

Submit to Lab 10 dropbox as Lab10-week8_LastName_FirstInital

Name____________________________ Date________________________

Section__________________________

Title:

Purpose:

Methods: Use the McConkey agar plate to determine the potential pathogenic bacteria properties

Lab manual page 247 -250

1) Three samples of bacteria growing on a MacConkey plate

The bacteria plated are Providencia stuatii, Eschericia coli and Staphylococcus epidermidis

Results- bacteria colony description on the agar plates

Plate A

Plate B

Plate C

Growth on plate

Growth +

Growth +

Growth –

Lactose fermentation

Lactose fermentation present

Lactose fermentation negative

N/A

Find and add a picture to illustrate the different outcomes on McConkey agar

Discussion:

Use not applicable (NA) if needed.

McConkey agar is used to isolate and differentiate member of the ______________________ (family name) based on the ability to ferment lactose.

The selective ingredients in the McConkey agar plate include Neutral Red and ______________.

The differential ingredient in the McConkey agar plate is _____________.

Plate A was inoculated and incubated at 37C. The isolated colonies on this plate were able to __________________. This was identified by the _______________ color of the agar. The identification of the bacteria grown on this plate is __________________________.

Plate B was inoculated and incubated at 37C. The isolated colonies on this plate were able to __________________. This was identified by the _______________ color of the agar. The identification of the bacteria grown on this plate is __________________________.

Plate C was inoculated and incubated at 37C. The isolated colonies on this plate were able to __________________. This was identified by the _______________ color of the agar. The identification of the bacteria grown on this plate is __________________________.