Sodium phosphate dibasic heptahydrate is a laboratory chemical used in phosphate buffers and other research applications. The best choice depends on whether you need stated purity, an ACS-grade label, a general-purpose 500-gram container, or an anhydrous form for a different preparation. The products below include four heptahydrate options and one anhydrous alternative, which is not a direct substitute when a procedure specifies the heptahydrate.
| Product | Best for | Key distinction |
|---|---|---|
| Innovating Science Ultrapure Heptahydrate | Purity-focused research | At least 99.0% purity; RNase and DNase free |
| Innovating Science Anhydrous | Procedures calling for anhydrous material | Different hydration state |
| Curated Chemical Collection Heptahydrate | General lab and educational use | 500-gram bottle |
| Sodium Phosphate Dibasic 99% Minimum | Buyers comparing stated minimum purity | 500 grams; hydration state not specified in features |
| ACS Grade Heptahydrate | Research or further manufacturing use | ACS grade stated in product name |
Innovating Science Ultrapure Heptahydrate
This product is best for laboratory buyers who need a heptahydrate with clearly stated purity and handling characteristics. Its listed purity is at least 99.0%, and the product is described as RNase and DNase free. The listing says it is used in buffer formulation, pH stabilization, and biochemical studies.
For a 5% aqueous solution, the stated pH range is 8.7–9.3. The manufacturer also describes the reagent as soluble and capable of forming a clear, colorless solution. These specifications make it the most detailed option here for buyers checking solution behavior as well as chemical form.
- Best for: Research applications where the stated purity and nuclease-free description are relevant.
- Limitation: The stated pH range applies to a 5% aqueous solution; it should not be treated as the pH of every buffer recipe.
Innovating Science Anhydrous Sodium Phosphate
This is an anhydrous sodium phosphate dibasic product, not sodium phosphate dibasic heptahydrate. It is included as a useful comparison for buyers whose protocol specifies the anhydrous form. The listing describes it as a laboratory-grade buffering agent for biochemical work, chemical synthesis, and analytical chemistry.
Its stated uses include phosphate-buffered saline, Tris-phosphate, and saline-phosphate buffers. The description also mentions DNA/RNA extraction, electrophoresis buffers, enzymatic activity, and protein stability. Choose this product only when its anhydrous form matches the procedure and formulation you intend to follow.
- Best for: Buyers who specifically need anhydrous sodium phosphate dibasic for buffer preparation or laboratory work.
- Limitation: Avoid it if your method calls for the heptahydrate; the forms have different water content and are not interchangeable by equal mass.
Curated Chemical Collection Heptahydrate
This 500-gram sodium phosphate dibasic heptahydrate is best for general laboratory and educational use, based on the listing’s stated purpose. The product is also described for use as a cleaning agent. Its straightforward product description may suit buyers who need the named hydrate and a larger bottle for routine applications.
The available features do not provide a purity percentage, detailed solution data, or a specific buffer-performance range. Compare those missing details with your lab’s requirements before choosing it for a procedure that sets tight reagent specifications.
- Best for: General-purpose lab or educational settings seeking a 500-gram heptahydrate product.
- Limitation: The listed features do not state a purity grade or buffer pH specification.
Sodium Phosphate Dibasic, 99% Minimum
This 500-gram product is best for buyers comparing a stated minimum purity, which the listing gives as 99%. The feature information also describes the product as having an indefinite shelf life. However, the provided features do not specify whether it is the heptahydrate or another hydration state.
That distinction matters when calculating reagent quantities from a protocol. Confirm the product’s exact chemical form and label information before selecting it for work that explicitly requires sodium phosphate dibasic heptahydrate.
- Best for: Buyers seeking a 500-gram sodium phosphate dibasic product with a stated 99% minimum.
- Limitation: Hydration state is not identified in the supplied product features, so it is not the clearest match for a heptahydrate-specific method.
ACS Grade Heptahydrate
This product is best for buyers looking for sodium phosphate dibasic heptahydrate with an ACS-grade designation in the product name. The listing identifies a 500-gram quantity and categorizes it as a biochemical buffer. It also states that the product is sold for research or further manufacturing use only.
The use restriction is important: the listing says it is not for food or drug use. The supplied features do not provide a numerical purity percentage or additional solution specifications, so buyers should check the product labeling against their application requirements.
- Best for: Research or further manufacturing applications where an ACS-grade heptahydrate listing is appropriate.
- Limitation: Not intended for food or drug use, according to the product description.
Buying Guide: How to Choose Sodium Phosphate Dibasic Heptahydrate
Does your procedure specify the heptahydrate?
Check the exact chemical form in your protocol and on the product label. Heptahydrate contains water of crystallization, while anhydrous sodium phosphate dibasic does not. Because their formula weights differ, equal masses do not supply equal amounts of the compound. Do not substitute one form for the other without recalculating and confirming the method’s requirements.
Which purity and grade details matter?
Compare the exact specifications your work requires. The ultrapure option states at least 99.0% purity and RNase and DNase-free status. The ACS-grade option states its grade in the product name, while other listings provide less detail. A general product description should not be treated as equivalent to a specified purity or grade.
What quantity and application are appropriate?
Several products are listed in 500-gram quantities, while the anhydrous alternative is listed as 100 grams. Consider expected use, storage practices, and whether the product’s stated purpose matches your work. For buffer preparation, follow your validated recipe and account for the hydration state rather than relying on a generic concentration conversion.
Frequently Asked Questions
What is sodium phosphate dibasic heptahydrate used for?
It is used in laboratory research, phosphate buffer formulations, pH stabilization, and biochemical applications. Specific uses depend on the product and the procedure.
Is sodium phosphate dibasic heptahydrate the same as anhydrous sodium phosphate dibasic?
No. The heptahydrate contains seven water molecules per formula unit; the anhydrous form does not. Their mass-based calculations differ.
Which option states a purity percentage?
The Innovating Science ultrapure heptahydrate lists purity of at least 99.0%. The separate 500-gram dibasic product states a 99% minimum, but its supplied features do not identify its hydration state.
Can ACS-grade heptahydrate be used for food or drugs?
The ACS-grade listing says it is for research or further manufacturing use only and not for food or drug use.
Should the 5% solution pH apply to every buffer recipe?
No. The 8.7–9.3 pH range is stated for a 5% aqueous solution of the ultrapure product. Buffer pH depends on the formulation and preparation conditions.