Double Labeled Water (DLW) is purified water that is enriched with both ¹⁸O and D isotopes.  DLW is commonly used in the determination of energy expenditure.  Although CIL offers custom formulations of DLW to meet any combination of ¹⁸O and D enrichments, some researchers may prefer to prepare their own DLW using purified water and ¹⁸O enriched water and deuterium oxide of known enrichments.

• Please use our calculator titled "DLW Formulation Calculator" to calculate amounts of starting materials (¹⁸O-enriched water, deuterium oxide, and purified water) required to prepare a user-defined quantity of DLW of known ¹⁸O and D enrichment. 
   
• Please use our calculator titled "DLW Enrichment Calculator" to calculate the final ¹⁸O and D enrichments of a user-defined mixture of ¹⁸O enriched water, deuterium oxide and purified water.