How to T‐Streak (Microbiology)
Flip to the back of a sterile petri dish containing agar., Draw another line starting from the left side of the back plate until you hit the other side., Label the back plate of the petri dish with relevant laboratory information such as your...
Step-by-Step Guide
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Step 1: Flip to the back of a sterile petri dish containing agar.
Draw a line starting slightly above the center point.
Continue drawing the line until you hit the back plate's edge. , This new line should be perpendicular to the original line, intersecting it at the starting point.
The back plate of the petri dish should now be divided into three sectors, appearing as a large “T”. ,,, The object is to have the inoculation loop be slightly above the inner blue cone of the flame.
Hold it there for several seconds. , At this point, the loop is sterile and extremely hot.
The inoculation loop must be cooled, or else the residual heat will kill any bacteria taken from the culture. , Lift the lid of the petri dish just enough to insert the loop.
Touch the outer edge of the nutrient agar.
A sizzling sound should be heard upon first contact.
Continue holding the inoculation loop against the surface for several seconds. , Avoid touching any other surface at this point, doing so will recontaminate the inoculation loop., Open the source of your culture such as broth culture., Do this for several seconds. ,, Beginning in the top sector of the “T’, lightly drag the inoculation loop across the surface of the nutrient agar in a zigzag pattern.
It is important to stay within the region in which you are currently inoculating. , Follow the method described in Sterilizing the Inoculation Loop.
Remember to cool the inoculating loop on the edge of the nutrient agar that has not been contaminated with the original culture!,, Lightly drag the inoculation loop across nutrient agar toward the second sector., Lightly drag the inoculation loop across the nutrient agar in a zigzag pattern. , Follow the method described in Sterilizing the Inoculation Loop.
Remember to cool the inoculating loop on the edge of the nutrient agar that has not been contaminated with the original culture!,, Lightly drag the inoculation loop across the nutrient agar towards the third sector., Lightly drag the inoculation loop across the nutrient agar in a zigzag pattern. -
Step 2: Draw another line starting from the left side of the back plate until you hit the other side.
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Step 3: Label the back plate of the petri dish with relevant laboratory information such as your initials
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Step 4: time and culture source.
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Step 5: Begin by connecting the Bunsen burner to a fuel source and igniting it.
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Step 6: Insert the loop into the flame at a vertical angle.
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Step 7: Remove the loop from the flame.
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Step 8: Cool the inoculating loop.
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Step 9: Remove the inoculation loop from the petri dish.
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Step 10: Hold the sterile inoculation loop.
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Step 11: Insert the loop into the culture
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Step 12: swirling the contents to insure even distribution of bacteria within.
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Step 13: Remove the loop and recover the original sample.
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Step 14: Lift the lid of the petri dish just enough to insert the loop.
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Step 15: Re-sterilize the inoculation loop now that the first sector of the “T” has been inoculated.
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Step 16: Rotate the petri dish 90 degrees and lift the lid just enough to insert the loop.
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Step 17: Start in the first sector.
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Step 18: Continue into the second sector.
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Step 19: Re-sterilize the inoculation loop now that the second sector of the “T” has been inoculated.
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Step 20: Rotate the petri dish 90 degrees and lift the lid just enough to insert the loop.
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Step 21: Start in the second sector.
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Step 22: Continue into the third sector.
Detailed Guide
Draw a line starting slightly above the center point.
Continue drawing the line until you hit the back plate's edge. , This new line should be perpendicular to the original line, intersecting it at the starting point.
The back plate of the petri dish should now be divided into three sectors, appearing as a large “T”. ,,, The object is to have the inoculation loop be slightly above the inner blue cone of the flame.
Hold it there for several seconds. , At this point, the loop is sterile and extremely hot.
The inoculation loop must be cooled, or else the residual heat will kill any bacteria taken from the culture. , Lift the lid of the petri dish just enough to insert the loop.
Touch the outer edge of the nutrient agar.
A sizzling sound should be heard upon first contact.
Continue holding the inoculation loop against the surface for several seconds. , Avoid touching any other surface at this point, doing so will recontaminate the inoculation loop., Open the source of your culture such as broth culture., Do this for several seconds. ,, Beginning in the top sector of the “T’, lightly drag the inoculation loop across the surface of the nutrient agar in a zigzag pattern.
It is important to stay within the region in which you are currently inoculating. , Follow the method described in Sterilizing the Inoculation Loop.
Remember to cool the inoculating loop on the edge of the nutrient agar that has not been contaminated with the original culture!,, Lightly drag the inoculation loop across nutrient agar toward the second sector., Lightly drag the inoculation loop across the nutrient agar in a zigzag pattern. , Follow the method described in Sterilizing the Inoculation Loop.
Remember to cool the inoculating loop on the edge of the nutrient agar that has not been contaminated with the original culture!,, Lightly drag the inoculation loop across the nutrient agar towards the third sector., Lightly drag the inoculation loop across the nutrient agar in a zigzag pattern.
About the Author
Richard Robinson
Enthusiastic about teaching practical skills techniques through clear, step-by-step guides.
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