Let's go Streaking!

Ok, not that kind of streaking. I'm referring to a technique used to spread bacterial colonies on an agar plate. A sterile loop or cotton swab is dipped into the bacterial culture or patient sample that contains many different kinds of bacteria. This swab or loop is then spread over a growth medium known as agar. One will choose what type of agar to use depending on the bacteria that is being tested for. If you've ever had strep throat your doctor most likely took a throat culture and had it tested. The culture was spread over an agar plate with nutrients that favor bacterial growth. If bacterial colonies develop over the next 24 to 48 hours the test is positive and you have strep throat. Once you have streaked a mixed bacterial culture, you may then remove individual colonies with a loop or needle and subculture them on a new plate. Parter Medical, Greiner Bio-one, and BD all make products used for streaking.