D9779 Sigma


for molecular biology, ≥98% (HPLC), ≥99% (titration)

Synonym: threo-1,4-Dimercapto-2,3-butanediol, Cleland’s reagent, DTT




An excellent reagent for maintaining SH groups in reduced state; quantitatively reduces disulfides. DTT is effective in sample buffers for reducing protein disulfide bonds prior to SDS-PAGE. DTT can also be used for reducing the disulfide bridge of the cross-linker N,N′-bis(acryloyl)cystamine to break apart the matrix of a polyacrylamide gel. DTT is less pungent and is less toxic than 2-mercaptoethanol. Typically, a seven fold lower concentration of DTT (100 mM) is needed than is used for 2-mercaptoethanol (5% v/v, 700 mM).

DL-Dithiothreitol has been added to the samples before loading them for SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis). It has been used in the procedure of in situ hybridization of mRNA.


1, 5, 10, 25, 50 g in poly bottle

250 mg in poly bottle

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LC-MS Grade Solvents and Reagents

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Safety & Documentation

Safety Information

GHS07  GHS07
Signal word 
Hazard statements 
Precautionary statements 
Personal Protective Equipment 
UN 3335
WGK Germany 
Flash Point(F) 
235.4 °F
Flash Point(C) 
113 °C

Frequently Asked Questions

Which document(s) contains shelf-life or expiration date information for a given product?
If available for a given product, the recommended re-test date or the expiration date can be found on the Certificate of Analysis. These documents are located on the product detail page under Useful Links & Tools. Click on the following link to search for a Certificate of Analysis. Please click the following link to see the details on our Product Dating Information.
How do I get lot-specific information or a Certificate of Analysis?
A Certificate of Analysis is available by lot number and can be obtained through our Advanced Search Option:
What is the shelf life of Product D9779, DL-Dithiothreitol?
The recommended retest period for D9779 is 4 years. This information can be found on the Specification Sheet. The actual retest date for a given lot can be found on the Certificate of Analysis for that lot. Here is the link to the specification sheet:
What is the solubility of Product D9779, DL-Dithiothreitol?
This product is soluble in water (50 mg/mL), yielding a clear, colorless solution. DTT is also soluble in ethanol, acetone, ethyl acetate, chloroform and ether. This information may be found on the product information sheet for a related DTT product (Product No. D0632). Here is the link to that document:
What is the solution stability of Product D9779, DL-Dithiothreitol (DTT)?
We generally recommend preparing DTT solutions fresh daily. A table showing the half life of DTT in solution under various conditions can be found on the product information sheet for a related DTT product (Product No. D0632). Here is the link to that document:
What is the meaning of Molecular Biology Grade in the description of Product D9779, DL-Dithiothreitol?
Molecular Biology grade products are tested for DNase, RNase, and protease to make certain that they contain minimal levels of these contaminants.
How do I find price and availability?
There are several ways to find pricing and availability for our products.  Once you log onto our website, you will find the price and availability displayed on the product detail page. You can contact any of our Customer Sales and Service offices to receive a quote.  USA customers:  1-800-325-3010 or view local office numbers. 
What is the Department of Transportation shipping information for this product?
Transportation information can be found in Section 14 of the product's (M)SDS. To access the shipping information for this material, use the link on the product detail page for the product, or search here. 
My question is not addressed here, how can I contact Technical Service for assistance?
Use the option to the right to "Ask a Question" by email of a Technical Service Scientist.
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