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His-Tag Check&Go! Protein Expression and Purification

Immunochromatography test for His-tagged proteins in less than 15 minutes

The His-Tag Check&Go! kit is a quick and easy competitive immunochromatography test that has been developed to allow scientists to verify and monitor successful expression of His-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, His-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 containing a ‘Test line’ of immobilized His-Tag protein on the ‘Test line’ (T line) and a ULFA-tagged protein on the ‘Control line’ (C line). A 40nm InnovaCoat®-GOLD anti-His-Tag antibody and 40nm InnovaCoat®-GOLD anti-ULFA tag conjugate are used for detection.

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 his-tagged protein levels
• Compatible with Amintra™ CoHis, NiHis and Ni-NTA resins
• Unique to Expedeon

* Subject to protein yield

Results

If your sample does not contain any His-tagged protein, the T line will appear as a strong red line (Figure A: -His-tagged protein).

If your sample does contain His-tagged protein, the T line will not be visible (or it will appear as a pale red line) as it competes with the binding of the InnovaCoat® -GOLD anti-His-Tag antibody conjugate to the antigen immobilized on the T line (Figure B: +His-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.

Buffer Compatability

1X PBS
Fully compatible
1X TBS
Fully compatible
RIPA buffer
Fully compatible
Tween20
< 5%
CHAPS
< 1%
Triton
< 5%
SDS< 1%
Dodecyl Maltoside < 5%
Imidazole
< 125mM
Guanidine HCl
< 100mM
Urea< 125mM
DTT
< 100mM
2-mercaptoethanol< 100mM
EDTA< 100mM
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Protein Screening and Sensitivity


Six different recombinant proteins were diluted down to 300, 100, 33 and 11ug/ml in 1X Running Buffer and run on a HisTag Check&Go! strip. The strips were analysed using the EseQuant reader (Qiagen). Signal suppression is clearly detected in all the proteins tested.

Buffer Compatability

Cell Lysate

Non induced (-I) and induced (I) E. coli cell lysates expressing recombinant protein His-GST in 1X Running Buffer

Can I use re-use the His-Tag Check&Go! strips?
No, as the His-Tag Check&Go! strips are designed for single use only.

Can I use the His-Tag Check&Go! strips to quantify my His-tagged protein?
The His-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 His-Tag Check&Go! strips at room temperature instead of +4°C, can I still use them?
Yes, you can – the His-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 His-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 contains plenty of His-tagged protein. To confirm the result, dilute your sample further until the T line appears.

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 His-Tag Check&Go! strip.