BIOS 242 Week 1 Lab 1; Culture Transfer Techniques

Institution	BIOS 242 Fundamentals of Microbiology with Lab - Chamberlain
Contributor	Anika Fultz

Lab 1: Culture Transfer Techniques

Identify the importance of aseptic technique in the field of microbiology
Apply the concept of aseptic technique and its importance in the field of microbiology.
Identify different forms of basic growth media
Transfer a pure bacterial culture from one growth media to another, a process called sub- culturing.

Nutrient broth, Nutrient agar slants, Nutrient agar stabs, liquid and slant cultures of Serratia marcescens,

inoculating loop, inoculating needle, incinerators

Remove extraneous materials from the lab bench and disinfect it with 10% bleach solution.
Obtain 24 hour cultures of Serratia marcescens (broth and slant).
Label the sterile tubes (broth, slant, and stab) with the name of the organism and your group designation.
Loop sterilization for those labs with reusable metal loops following the instructions below (a and b). If your lab uses sterile plastic loops, use a new loop for each transfer being mindful not to touch it on any surface.
Transfer from a broth culture to a new broth culture by following the steps outlined in a-h.
Transfer from a broth culture to a slant culture
Transfer from a broth culture to a slab culture
Transfer from a slant culture to a broth, slant, or stab culture
When finished, incubate the tubes at approximately 25^o C for 24 to 48 hours.

Examine the cultures for appearance of growth. Broth cultures should appear turbid (cloudy). Slant and stab cultures should have orange-red growth on the surface of the slant and along the line of inoculation in the slant culture.
Record your findings in the Lab Report.

Please describe in complete sentences and in your own words, the purpose of this experiment. Allows us to practice the sterile technique

Broth Stock Culture: EC

Questions:

Why is proper aseptic technique important in microbiology?
What is the importance of flaming the inoculating loop or needle before and after each inoculation?
If you do not wait 10 – 20 seconds after flame sterilizing the inoculating instruments before obtaining the sample, what might be the consequences?
Why is it important to flame neck of the tubes immediately after uncapping and before recapping the tubes?
The stab tube was inoculated with a needle. Why was this used instead of the inoculating loop?
The Serratia marcescens cultures were accidently incubated at 37^o C instead of 25^o C. You observed growth but the slant and stab cultures were white, not orange-red. Does this mean your sample was contaminated?