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GST-Tag Check&Go! kit

Immunochromatography Test for GST-Tagged Protein Expression in Less Than 15 Minutes

The GST-Tag Check&Go! kit is a quick and easy sandwich lateral flow test that has been developed to allow scientists to verify and monitor successful expression of GST-tagged recombinant proteins in one easy step, prior to performing other downstream applications.

Unlike traditional methods of assessing the success of your protein expression and purification, which can be tedious and time consuming, GST-Tag Check&Go! is a simple qualitative immunochromatography test that requires only 10–15 minutes of your time and very small quantities of your sample.

The key component of the kit is a nitrocellulose membrane with a conjugate pad containing a mixture of anti-GST antibody, conjugated to either 40nm gold nanoparticles or CaptSure™ peptide whilst the “Test line” (T line) on the nitrocellulose contains an antibody which binds the CaptSure™ peptide. The intensity of the T-line correlates with the amount of GST-tagged protein in the sample.

The conjugate pads also contain biotin-gold, which binds streptavidin on the “Control Line” (C line) of the nitrocellulose strips. Hence, the C line is assay-independent and should always appear as a strong red line.

Each kit contains a vial of freeze-dried GST-tagged protein, which should be used as a positive control for the assay.

Why Choose Check&Go! for Qualitative Immunochromatography Tests?

  • Quick yes / no answer during expression and purification processes
  • Results in less than 15 minutes!
  • Compatible with cell culture media and lysate
  • Easy to use
  • Cheaper than gel electrophoresis / Western blot
  • Small sample volume required: 80ul diluted* sample / strip
  • Stable ‘C line’ signal intensity: Independent from GST-Tagged protein levels
  • Compatible with Amintra® Glutathione Affinity Resin and Amintra® Glutathione Magnetic Resin

* Subject to protein yield

Easy Visualization of Results for GST-Tag Check&Go! Expression Validation Kit:

If the sample does contain GST-Tagged protein, a strong T line will be visible as it interacts with the mixture of the InnovaCoat®-GOLD anti-GST Tag antibody conjugate and CaptSure™ peptide anti-GST Tag antibody conjugate, forming a ‘sandwich’, which can then bind to the antibody immobilized on the T line (see above: A: +GST tagged protein)

If the sample does not contain any GST-Tagged protein, the T line will not be visible or may appear as a weak line (see above: B: -GST tagged protein)

The C line is assay independent and should always appear as a strong red line; if it is not visible, the test is not valid and should be repeated.

Assay compatibility and interfering substances:

1X PBSFully compatible
1X TBSFully compatible
RIPA bufferFully compatible
Tween20< 2%
CHAPS< 1%
Triton< 0.5%
SDS< 0.01%
Imidazole< 50mM
Guanidine HCl< 1mM
Urea< 125mM
DTT< 20mM
2-mercaptoethanol< 50mM
EDTA< 50mM

Related Products:

Expedeon also offers a range of products to enable the purification of GST tagged recombinant proteins. These include our Amintra™ Glutathione Affinity Resin and  Amintra™ Glutathione Magnetic Resin.

Can I use re-use the GST Tag Check&Go! strips?

No, as the GST Tag Check&Go! strips are designed for single use only.

Can I use the GST Tag Check&Go! strips to quantify my GST tagged protein?

The GST Tag Check&Go! strips provide a qualitative yes / no answer, although a semi-quantitative measurement of the abundance of protein in the sample can be determined using internal references and controls.

I have accidentally stored the GST Tag Check&Go! strips at room temperature instead of +4°C, can I still use them?

Yes, you can – the GST Tag Check&Go! strips are shipped at ambient temperature and storage at room temperature for a short time will not affect the performance of the kit. The expiry date is 2 years for the strips and 3 years for the buffer.

I don’t see the Test line on the GST Tag Check&Go! strip – what should I do?

If the Test (T) line does not appear, but the Control (C) line is clearly visible, it means that your sample may not contain GST tagged protein or may be out of the detection range. To confirm the result, ensure your sample is within the optimal concentration range (100ng/ml – 1µg/ml) and re-test. If you are unsure of your sample concentration, perform serial 1:10 dilutions and check each dilution.

My sample is not running – what should I do?

Make sure that the conjugate pad and the nitrocellulose are making physical contact with a pipette tip or by gently bending the GST Tag Check&Go! strip.

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