ADIFAB

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ADIFAB (Acrylodan labeled Intestinal Fatty Acid Binding Protein) is a fluorescent molecule that enables you to assay the aqueous concentration of free fatty acids, also known as unbound free fatty acids.

The assay can be used in a variety of biochemical and clinical applications including the determination of lipase activity, fatty acid binding to membranes and proteins, and serum unbound free fatty acid levels. 

Assay Method

You can determine unbound free fatty acid levels in an aqueous solution  with a simple, one step procedure that completes in approximately one minute:  add a small amount of the ADIFAB reagent to a solution suspected of containing unbound free fatty acid and measure the resulting fluorescence. In the  absence of unbound free fatty acids, the ADIFAB probe fluoresces in the blue at 432 nm. In the presence of unbound free fatty acids, the emission  shifts to the green with a peak at 505 nm. The ratio of fluorescence at 505 nm and 432 nm allows the concentration of unbound free fatty acids to be determined without further calibration. For further details, refer to the protocols.

Storage

ADIFAB should be stored frozen upon receipt and should be protected from  light. After ADIFAB is brought up in solution, it should be refrigerated not frozen. The product is stable in a storage buffer at 4°C for >3 months.

Characteristics

• Accuracy: to greater than 1 nM depending on type of FA
• Purity : Gel electrophoresis > 95%
• Form: Lyopholized powder
• Weight: 15000 Da

Patent Number 5,470,714

Safety

ADIFAB does not contain any hazardous components above 1% or any carcinogens above 0.1% as defined in 29 CFR 1910.1200, the OSHA Hazard Communication Standard.

ADIFAB2 (Acrylodan labeled Intestinal Fatty Acid Binding Protein) is a fluorescent molecule that enables you to assay the aqueous concentration of free fatty acids, also known as unbound free fatty acids, in a simple procedure that completes in approximately one minute. 

The assay can be used in a variety of biochemical and clinical applications including the determination of lipase activity, fatty acid binding to membranes and proteins, and serum unbound free  fatty acid levels. 

ADIFAB2 is a high affinity version of the original ADIFAB probe. ADIFAB2, similarly to ADIFAB,  can be used to assay unbound free fatty acid levels but provides greater sensitivity for low concentrations of the FFA levels. For those concentrations below about 400 nM, the increase in the ADIFAB2 emission ratio is about twice that for ADIFAB.

Also, ADIFAB2 fluorescence emission spectra occur at longer wavelengths. Binding affinities for ADIFAB2 are approximately ten times greater than for ADIFAB. On the other hand, ADIFAB has a wider range of sensitivity than ADIFAB2 and is preferable for higher concentrations of unbound free fatty acids.

Assay Method

You can determine unbound free fatty acid levels in an aqueous solution with a simple, one step procedure: add a small amount of the ADIFAB2 reagent to a solution suspected of containing unbound free fatty acid and measure the resulting fluorescence.  Although the assay method for ADIFAB2 is similar to that for ADIFAB, the excitation and emission wavelengths are different. The excitation  value for ADIFAB2 is 375 nm and the emission wavelengths are 550 and  457 nm. 

Characteristics

• Accuracy: to greater than 1nM depending on FA type             
• Purity : Gel electrophoresis > 95% 
• Form: Lyopholized powder 
• Weight: 15000 Da 

Storage

ADIFAB2 should be stored frozen and protected from light. After ADIFAB2 is brought up in solution, it should be refrigerated not frozen. The product is stable in a storage buffer at 4°C for >3 months.

Patent Number 5,470,714

Safety

ADIFAB2 does not contain any hazardous components above 1% or any carcinogens above 0.1% as defined in 29 CFR 1910.1200, the OSHA Hazard Communication Standard.

FFA Sciences is developing new fluorescent probes. These probes have enhanced  specificity for individual FFA and other metabolites.

New FFA specific probes include: PAL, a high affinity probe with enhanced specificity for palmitate (16:0) and OAL, a high affinity probe with enhanced specificity for oleate (18:1). 

These and other FFA specific probes such as Arachidonic, DHA, Linoleic and Stearic have been used to determine the profile of different unbound FFA in mixtures of FFA in equilibrium with albumin as described in the following publication:

Fatty Acid-Specific Fluorescent Probes and  Their Use in Resolving Mixtures of Unbound Free Fatty Acids in Equilibrium with Albumin Andrew H. Huber, J. Patrick Kampf, Thomas Kwan, Baolong  Zhu, and Alan M. Kleinfeld Biochemistry; 2006; 45:14263-14274

For more information refer to: Protocols.

FFA Sciences can as a service provide profiles in biological samples. Contact us for more information.

I-FABP is recombinant rat intestinal fatty acid binding protein. Fatty acid binding proteins (FABP) form a family of small, 14-15 kDa, proteins found in the cytosol of a variety of mammalian tissues. 

The proteins bind long chain fatty acids and are involved in the regulation and transport of intracellular free fatty acids. Our product, I-FABP is delipidated and supplied as a lyophilized powder in 1, 5, and 10 mg sizes. 

Characteristics

• Purity : > 95% as determined by reverse phase  HPLC  
• Form: Lyopholized powder 
• Weight: 15000 Da 

Storage

I-FABP should be stored frozen upon receipt. AfterI-FABP is brought up in a solution, it should be refrigerated. The product is stable in a storage buffer at 4°C for >3 months.

Safety

I-FABP does not contain any hazardous components above 1% or any carcinogens above 0.1% as defined in 29 CFR 1910.1200, the  OSHA Hazard Communication Standar

FFAu Standards are calibrated aqueous solutions of fatty acids complexed with bovine serum albumin. The standards can be provided for several different fatty acids, including oleate, linoleate and arachidonate. Other standards  are available from FFA Sciences upon request.

Standards other than oleate are provided on a custom basis.

Assay Method

The standards are provided as fatty acid complexes with 600 µM BSA in a HEPES/saline buffer at pH 7.4. They are typically used as dilutions of the 600 µM stock and retain their ability to buffer unbound free fatty acid levels at dilutions exceeding 100:1. For further details, refer to the protocols. 

Accuracy

Accurate to about 1nM depending on type of FA

Storage 

The standards are sold in a buffered solution. They can be kept frozen and the unbound free fatty acid values appear to be stable over repeated (>10) freeze/thaw cycles. The free fatty acid values also appear to be stable when refrigerated, at the stock concentration, for at least 1 month.

Safety

FFAu Standards do not contain any hazardous components above 1% or any carcinogens above 0.1% as defined in 29 CFR 1910.1200, the OSHA Hazard Communication Standard.

Scientists at FFA Sciences can advise you on how best to utilize our products and methods. They can provide the following services: 

• Measure FFAu Levels  We can measure FFAu levels in your samples of biological fluids such as blood, lymph, and interstitial fluids. Also, contact us for information about assays currently in development in our metabolomics program. These probes can be used in the determination of specific  FFAu (FFAu profiles).  
• Enable High Throughput Screening for Drugs  We can help you screen for drugs that affect FFA metabolism in cells or enzymes using high throughput formats.   
• Determine Binding Affinities and Enzyme Activities  We can determine binding affinities for proteins (for example, FABP, PPAR, and albumin) or other macro molecules for  your choice of FFA. In addition, we can measure reaction kinetics in enzymes for which FFA are reactants or products.   
• Develop Assays for Unbound or Free Levels of  Metabolites  We will generate assays for your choice of  metabolites by screening our libraries of fluorescently labeled mutant FABPs for specific binding to the chosen metabolite.   
• Provide Fatty Acid Albumin Complexes We can provide user-defined complexes for use  in buffering FFAu levels and for instrument calibration. 

Please read our Limited Use Product License before ordering our products.