Difference between revisions of "PhiX:Serial dilution"

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m (Summary)
m (Summary)
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'''Stock Solution'''<br>
 
'''Stock Solution'''<br>
 
The stock solution has a titer = x PFU/ml (PFU = plaque forming units)<br>
 
The stock solution has a titer = x PFU/ml (PFU = plaque forming units)<br>
Alternatively =  y pfu in z ul<br>
+
Alternatively =  y PFU in z ul<br>
  
'''SERIAL DILUTION'''<br>
+
'''Serial Dilution Procedure'''<br>
Add 100ul (10<sup>-1</sup>x) phage to 900ul HFB and mix -> tube #1<br>
+
Prepare a set of labelled tubes from #1 to #8. Fill each tube with 900ul of HFB (or PBS will suffice).<br>
 +
Add 100ul (10<sup>-1</sup>x) stock phage to 900ul HFB and mix -> tube #1<br>
 
Transfer 100ul (10<sup>-2</sup>x) #1 to 900ul HFB and mix -> tube #2<br>
 
Transfer 100ul (10<sup>-2</sup>x) #1 to 900ul HFB and mix -> tube #2<br>
 
Transfer 100ul (10<sup>-3</sup>x) #2 to 900ul HFB and mix -> tube #3<br>
 
Transfer 100ul (10<sup>-3</sup>x) #2 to 900ul HFB and mix -> tube #3<br>
and so on...<br>
+
and so on...Do not forget to change tips and mix between transfers. <br>
thoroughly mix between<br>
 
  
'''PLATING'''<br>
+
'''Plating'''<br>
 
Tube #1 -> plate 100ul (1/10) -> 10<sup>-2</sup>x<br>
 
Tube #1 -> plate 100ul (1/10) -> 10<sup>-2</sup>x<br>
 
Tube #2 -> plate 100ul (1/10) -> 10<sup>-3</sup>x<br>
 
Tube #2 -> plate 100ul (1/10) -> 10<sup>-3</sup>x<br>

Revision as of 06:03, 20 February 2017

Summary

This protocol describes how to prepare serial dilutions in order to enumerate phage from a stock solution. Before you begin you should also prepare for the double agar overlay plaque assay onto which fresh dilutions should be plated.

Stock Solution
The stock solution has a titer = x PFU/ml (PFU = plaque forming units)
Alternatively = y PFU in z ul

Serial Dilution Procedure
Prepare a set of labelled tubes from #1 to #8. Fill each tube with 900ul of HFB (or PBS will suffice).
Add 100ul (10-1x) stock phage to 900ul HFB and mix -> tube #1
Transfer 100ul (10-2x) #1 to 900ul HFB and mix -> tube #2
Transfer 100ul (10-3x) #2 to 900ul HFB and mix -> tube #3
and so on...Do not forget to change tips and mix between transfers.

Plating
Tube #1 -> plate 100ul (1/10) -> 10-2x
Tube #2 -> plate 100ul (1/10) -> 10-3x
Tube #3 -> plate 100ul (1/10) -> 10-4x
and so on...

MATHS
E.g. count n plaques on plate from 10-7x plate:
x = n * 10-7
OR, if z = 200ul (e.g., mutagenesis)
y = (n * 10-7) * 200/1000

File:Dilution.pdf