Name: XpressCheck FLAG Tag Test Strip
SKU: XC-FLAG
Availability: InStock

Order through Avantor/VWR: Box of 25 / Box of 100.

Product Overview

The Instanosis XpressCheck FLAG-Tag Test Strip is a patent-pending, rapid, high-affinity lateral flow qualitative dipstick engineered for the immediate verification of FLAG-tagged recombinant fusion proteins. Designed to completely bypass the multi-hour workflow bottlenecks of traditional anti-FLAG Western blotting or colorimetric ELISAs, this protocol-ready strip confirms expression and maps target presence from micro-volume samples in under 3 minutes. Manufactured in the USA to rigorous quality standards, it provides a highly precise, instrument-free verification solution for core facilities, expression screening labs, and biopharmaceutical researchers evaluating protein synthesis or chromatography elution fractions at the bench.

Technical Specifications & Key Data

This specialized lateral flow verification dipstick is optimized to deliver high-efficiency analytical feedback across automated or manual protein expression and purification workflows:

Target Analyte: Recombinant fusion proteins expressing the standard FLAG epitope tag (DYKDDDDK peptide sequence).
Assay Format: Lateral flow dipstick.
Analytical Sensitivity Threshold: The detection limit of the strip is about 0.2 µM, corresponding to 10 µg/mL for a protein with a molecular weight of 50 kDa. With serial diluted samples the assay can also be carried out in a semiquantitative manner to determine the concentration of the FLAG tagged protein.
Micro-Volume Sample Consumption: Preserves precious recombinant proteins, using a fraction of the sample volume required for traditional Western blots.
Rapid Development Time: Definitive qualitative visual lines stabilize completely within 3 minutes.
Product Classification: For Laboratory Research Use Only (RUO). Not for use in clinical diagnostic procedures.

Research & Protein Purification Significance

In modern structural biology, therapeutic protein engineering, and academic core facilities, identifying target protein expression levels in real-time is crucial to avoiding downstream purification failures.

Elimination of the Western Blot Bottleneck: Traditional SDS-PAGE, transfer, blocking, and antibody incubation steps consume up to a full working day. The XpressCheck strip provides a visual “go/no-go” signal in minutes, speeding up transfection and expression optimization.
Chromatography Fraction Tracking: Rather than blindly pooling fractions from affinity or size-exclusion chromatography columns, researchers can dip a strip into fractions to pinpoint exactly where the target protein is eluting, optimizing protein concentrations before downstream analysis.
Crude Lysate Compatibility: The engineered lateral flow matrix tolerates complex cellular environments, allowing operators to verify protein presence directly within crude E. coli lysates, mammalian cell supernatants, or insect cell media without clarifying or purifying the sample first.

Ordering Options & Procurement Details

SKU: XC-FLAG
Packaging Configurations: Supplied in standard boxes of 25 or 100 individually pouched test strips (each dipstick is hermetically sealed in a heavy-duty moisture-barrier foil pouch containing an active desiccant packet to guarantee a stable 24-month shelf life at standard room temperature).
Procurement Pathways: Orderable through this website or primary scientific distribution catalogs such as Avantor / VWR (link above Product Overview).

Frequently Asked Questions (FAQ)

Q1: What specific tag does the XpressCheck Test Strip detect?

A: This rapid assay specifically targets the classic FLAG epitope tag containing the octapeptide sequence (DYKDDDDK), detecting it at either the N-terminus, C-terminus, or internal regions of the recombinant fusion protein.

Q2: What is the exact analytical sensitivity limit for this dipstick?

A: The XpressCheck FLAG-Tag strip features a detection limit of the strip is about 0.2 µM, corresponding to 10 µg/mL for a protein with a molecular weight of 50 kDa.

Q3: Can this test strip completely replace a Western blot?

A: For qualitative screening, expression confirmation, and tracking column elution fractions, yes. It provides a visual “yes/no” answer in minutes instead of hours. However, traditional Western blotting or mass spectrometry should still be used if you require molecular weight validation or exact quantitative data.

Q4: Is it necessary to clarify or purify crude cell lysates before running the test?

A: No. The test strip is specifically formulated to interact directly with crude cell lysates, clarified lysates, or raw cell culture supernatants, eliminating the need for complex sample prep or centrifugation before testing.

Q5: Is the XpressCheck FLAG-Tag Test Strip cleared for human diagnostic screening?

A: No. This product is strictly classified for Laboratory Research Use Only (RUO). It is engineered for protein expression monitoring, bioprocess optimization, and recombinant engineering validation, and is not intended for patient diagnostic use.

Q6: Can academic and corporate research labs purchase this kit through standard contract distributors?

A: Yes. Procurement departments can order the Instanosis Box of 25 or 100 strips using the specific product SKU through direct institutional purchase agreements or via established scientific distribution channels like Avantor/VWR.