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 DESCRIPTION  
 Alkaline Phosphatase catalyszes the removal of 5'-phosphate groups from DNA, RNA and ribo- and deoxyribonucleoside triphosphates.   
   
 SOURCE  
 Calf intestinal mucosa.  
   
 APPLICATIONS  
 ¡Ü Removing 5' phosphates from DNA or RNA  
 prior to end labeling 5¡¯ termini with 32P.  
 ¡Ü Removing 5' phosphates from fragments of  
    DNA to prevent self-ligation.  
   
 UNIT DEFINITION  
 One unit is defined as the amount of enzyme required to catalyze the hydrolysis of 1 ¥ìmol of 4-nitrophenyl- phosphate to 4-nitrophenol in 1 minute at 37¡É.   
 NOTE  
 Proteinase K is used to digest CIAP, which must be completely removed if subsequent ligatios are to work efficiently. An alternative method is to activate the CIAP by heating to 65¡É for 1 hour(or 75¡É for 10 minutes) in the presence of 5 mM EDTA(pH 8.0) and then to purify the dephosphorylated DNA by extraction with phenol:chloroform. 
  
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 STANDARD UNIT ASSAY CONDITIONS  
 1 M diethanolamine (pH 9.8), 0.5 mM MgCl2,  10.9 mM 4-nitrophenylphosphate.  
   
 CONCENTRATION: 1-5 unit/§¡.  
   
 10X REACTION BUFFER  
 500 mM Tris-HCl (pH 9.3), 10 mM MgCl2, 1 mM ZnCl2, 10 mM spermidine.  
   
 STORAGE CONDITIONS  
 10 mM Tris-HCl (pH £Ü8.0), 1 mM MgCl2, 0.1 mM ZnCl2, 50 mM KCl and 50% glycerol.  Store at -20¡É.¡¡   
   
 REFERENCE  
 1. Sambrook, J. and Russell, David W. (2001) Molecular Cloning: A Laboratory Manual, 3rd ed., Cold Spring Harbor Laboratory Press.  
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