Pierce™ Fluorescent Protease Assay Kit
Pierce™ Fluorescent Protease Assay Kit
Thermo Scientific™

Pierce™ Fluorescent Protease Assay Kit

The Thermo Scientific Pierce Fluorescent Protease Assay Kit measures total protease activity in samples, providing a means to assess theRead more
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Catalog number 23266
Price (USD)
309.00
Each
Add to cart
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Price (USD)
309.00
Each
Add to cart
The Thermo Scientific Pierce Fluorescent Protease Assay Kit measures total protease activity in samples, providing a means to assess the progress of protease isolation procedures or quantify protease contamination in biological samples.

This kit includes fluorescein-labeled casein as a substrate for assessing protease activity in a sample by either fluorescence resonance energy transfer (FRET) with a standard fluorometer or fluorescence polarization (FP) with capable instrumentation. FTC-Casein is native casein that has been labeled using a large molar excess of fluorescein isothiocyanate (FITC). Fluorescence properties of this heavily-labeled, intact protein substrate change dramatically upon digestion by proteases, resulting in a measurable indication of proteolysis.

Features of the Fluorescent Protease Assay Kit:

Casein substrate—measure activity of any protease that cleaves casein into peptide fragments
Trypsin standard—quantify protease activity relative to trypsin, a universally accepted reference
Sensitive—1000 times more sensitive than assays that use unmodified forms of casein
Simple and fast—test tube and microplate protocols are completed in less than one hour
Homogenous—addition steps only; no separation, transfer or stop steps required
Customizable—easily adapt time, temperature and pH to optimize sensitivity for proteases of interest

Applications:
• Assess functional integrity and overall progress of protease purification
• Quantify protease contamination in protein samples
• Characterize the activity of unusual proteases compared to trypsin
• Evaluate buffer conditions for their affects on protease function and activity

Additional Specifications:
• Substrate: fluorescein-labeled casein (FITC-casein); available separately as Part No. 23267
• Basis of assay: change in fluorescence resonance (FRET) or fluorescence polarization (FP)
• Measurement: instrument with fluorescein excitation and emission filters (485/538nm)

Related Products
Pierce™ Colorimetric Protease Assay Kit
FITC-Casein for Pierce™ Fluorescent Protease Assay Kit
For Research Use Only. Not for use in diagnostic procedures.
Specifications
AssayProtease Assay
Detection MethodFluorescence
Immunoassay Kit Format96-well Plate
Label TypeClassic Dye
Product LinePierce™
Product TypeProtein Activity Assay
SubstrateCasein
Substrate PropertiesProtein-Based Substrate
Substrate TypeProtease Substrate
Sufficient For2000 Microplate Assays
For Use With (Application)Fluorescence Polarization, FRET
For Use With (Equipment)Microplate Reader
Quantity2000 Test Kit
TargetProteases
Unit SizeEach
Contents & Storage
Sufficient For: 2000 microplate assays using an instrument fitted with a fluorescein filter set (ex/em 485 nm/538 nm)
• FTC-Casein, lyophilized, 2.5 mg
• TPCK Trypsin Standard, 50 mg
• TBS Buffer Pack (makes 500 mL), 1 pack

Store FTC-Casein and TPCK Trypsin at 4°C.

Frequently asked questions (FAQs)

In the Fluorescent Protease Assay Kit (Cat. No. 23266), I had poor reproducibility within my plate or across experiments. What could be the cause?

Variations in pipetting can directly contribute to assay error, especially in the FRET-mode, because the working reagent itself has some intrinsic background fluorescence. Use reverse-pipetting or other techniques to prevent the introduction of small air bubbles into the plate wells. In FP-mode, if the sample matrix contains very high amounts of interfering fluorescent material, better quality results may be obtained by subtraction of buffer blanks from the data used for the mP calculation. In addition, FP detection is very sensitive to the position of the optical head in relation to the center of the well with respect to its X and Y coordinates, especially with 384-well plates. This position-artifact may be identified as reproducible patterned data by positioning the plate for a second reading 180 degrees relative to the first reading. Ensure that the instrument read positioning settings are appropriate for the type of plate chosen.

Find additional tips, troubleshooting help, and resources within our Protein Assays and Analysis Support Center.

In the Fluorescent Protease Assay Kit (Cat. No. 23266), I saw no change in signal. What can I do?

Ensure that the instrument gain setting is sufficiently low to avoid saturating the instrument detector. For fluorescence readers containing multiple excitation/emission positions, ensure that “top/top” is selected for excitation/emission settings.

Find additional tips, troubleshooting help, and resources within our Protein Assays and Analysis Support Center.

Do you offer any protein assays that are protein specific?

We offer several “specialty” protein assays including: Protease assay kits (Cat. Nos. 23263 and 23266), Glycoprotein Carbohydrate Estimation Kit (Cat. No. 23260), Phosphoprotein Phosphate Estimation Kit (Cat. No. 23270), Quantitative Peroxide assay kits (Cat. Nos. 23280 and 23285), and Easy-Titer Assay kits for IgG and IgM.

Find additional tips, troubleshooting help, and resources within our Protein Assays and Analysis Support Center.