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TSAP Thermosensitive Alkaline Phosphatase

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TSAP Thermosensitive Alkaline Phosphatase

TSAP Thermosensitive Alkaline Phosphatase removes 5´ phosphate groups from DNA, thus preventing the recircularization and religation of linearized cloning vector DNA during ligation. TSAP is effective on 3´ overhangs, 5´ overhangs and blunt ends. The enzyme is also useful for preparing DNA for 5´ end-labeling by removing existing phosphate groups from the 5´ end.

Because TSAP is irreversibly inactivated by heating at 74°C for 15 minutes, the need for a DNA cleanup step before a ligation reaction is eliminated. TSAP is fully active in all Promega restriction enzyme reaction buffers, streamlining the restriction digestion, dephosphorylation and ligation reaction workflow. TSAP Thermosensitive Alkaline Phosphatase is provided with Promega MULTI-CORE™ Buffer.


  1. Sambrook, J. et al. (1989) Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York.

Units listed are MBU (molecular biology units).

Storage Buffer: 10mM Tris (pH 7.5 @ 25°C), 100mM NaCl, 50% glycerol.

Source: Bacteria.

QC Tests: Activity, SDS-PAGE/purity, endonuclease, DNase, RNase, blue/white cloning assay.

Unit Definition: One MBU is defined as the amount of enzyme required to dephosphorylate 1μg of pGEM® DNA with 3´ overhangs in 15 minutes at 37°C in a 50μl reaction using any Promega restriction enzyme buffer (except F). Dephosphorylation is defined as preventing >95% of the plasmid from ligating (analyzed by agarose gel electrophoresis).

Comparison of Alkaline Phosphatases.

Heat Inactivated Yes Yes No
Inactivation Temperature 74°C 65°C N/A
Incubation Time 15 minutes 15 minutes 2 × 30 minutes
Special Buffer Required/Recommended No Yes Yes
Active in All Promega Restriction Enzyme (RE) Buffers Yes Partially No
Units Required in Different RE Buffers 1–2 10 N/A
Blue/White Cloning Qualified Yes Yes Yes
TSAP and SAP offer the convenience of heat inactivation. Only TSAP does not require a special buffer and is active in all Promega restriction enzyme buffers, making it the most convenient and cost-effective choice.
*TSAP=Thermostable Alkaline Phosphatase; CIAP = Calf Intestinal Alkaline Phosphatase.
**SAP = Shrimp Alkaline Phosphatase. Shown for comparison only; product not offered by Promega.
N/A = Not applicable.


What's in the box?

Item Part # Size Available Separately

TSAP Thermosensitive Alkaline Phosphatase

M991A 1 × 100u

MULTI-CORE™ 10X Buffer

R999A 1 × 0.25ml View Product

Certificate of Analysis

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Use Restrictions

For Research Use Only. Not for Use in Diagnostic Procedures.

Storage Conditions


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