All
Ni-NTA HisSorb products are provided preblocked with BSA and charged with nickel
for immediate use. They are compatible with standard multichannel pipets as well
as automated plate washers and readers.Further information: QIAexpress Assay System
For assays using 6xHis-tagged biomolecules
Ni-NTA HisSorb Strips and Plates provide the power of the QIAexpress Ni-NTA System in solid-phase, multiwell format for convenient assay and screening of 6xHis-tagged biomolecules, even in crude lysates. Ni-NTA moieties 〞 which coat the entire surface of each well 〞 deliver effective, directed immobilization of functionally active 6xHis-tagged molecules, leading to more reliable and reproducible assay results and higher signal-to-noise ratios (see figure below) than are possible with other systems.
The QIAexpress, Detection and Assay Handbook, supplied with all QIAexpress detection and assay products, contains detailed example protocols and guidelines for designing and performing assays.
All
Ni-NTA HisSorb products are provided preblocked with BSA and charged with nickel
for immediate use. They are compatible with standard multichannel pipets as well
as automated plate washers and readers.
For maximum convenience when testing or optimizing a limited number of samples, Ni-NTA HisSorb Strips are supplied framed and sealed in racks of twelve 8-well strips. Ni-NTA HisSorb Plates offer an ideal format for economical high-throughput assays and automation. These 96-well plates are available in either transparent format for colorimetric assays, or opaque, white format for luminescence- and fluorescence-based assays.
High-quality plates and vigorous quality control measures ensure that QIAexpress HisSorb products provide uniform well-thickness for reliable and reproducible measurements using optical plate readers. High-quality manufacturing practices also ensure uniform binding, washing, and optical properties.
 |
6xHis-tagged thioredoxin was
diluted in PBS, pH 7.2, applied to either polystyrene plates ( A
,  ) or to Ni-NTA HisSorb
Strips ( B ,  ),
and incubated overnight at 4∼C. Three separate standard curves C
were prepared using each type of plate. The amount of immobilized
protein was determined by incubating with rabbit anti-thioredoxin
polyclonal antibody for 2 h at room temperature followed by
anti-rabbit每alkaline-phosphatase conjugate for 1 h at room temperature
and measuring AP activity using pNPP as substrate. |
Increased Discrimination in Schistosomiasis Diagnosis
 |
Comparison of Ni-NTA HisSorb Strips with a polystyrene plate in diagnosis of schistosomiasis by immunoassay using 6xHis-tagged Schistosoma mansoni antigen Sm32. Infected serum samples (diluted 1:200) were those of school children in Mali. One sample (P) was a pool of 3 infected sera. Control sera were obtained from uninfected lab workers in Mali (CM) or Germany (CG). Detection was performed using alkaline phosphatase-labeled goat anti-human IgG-Fc, and the substrate pNPP. Blanks (B) were untreated wells incubated with substrate only. (Data kindly provided by T. Rinnert and E. Beck, Justus Liebig University of Gießen, Germany.) |
Detection of 6xHis-tagged Thioredoxin in Crude Lysates
 |
Thioredoxin, either alone or mixed with crude lysate from E. coli (200 µl, 5 µg/ml total protein), was bound to Ni-NTA HisSorb Strips and quantified by incubation with anti-thioredoxin polyclonal antibody for 2 h and anti-rabbit每alkaline-phosphatase conjugate for 1 h at room temperature followed by determination of enzyme activity using pNPP. As a control, nontagged protein was also applied. |
Ni-NTA HisSorb Strips and Plates are suitable for a range of applications:
If higher throughput is needed, various plates are also available in bulk quantities on demand. Besides the 96-well plates, Ni-NTA HisSorb Plates are also available in 384-well format in bulk quantities (minimum order 100 plates, please allow six weeks for delivery) for economical, high-throughput applications. In addition, black Ni-NTA HisSorb Plates in 96- and 384-well format are available for use with fluorescent substrates. While Ni-NTA HisSorb plates are suitable for most experiments, the specificity of the assay system can be increased further by using Anti﹞His Antibody Plates, available in transparent 96- and 384-well formats.
| Specifications | |||
| Product | Ni-NTA HisSorb Strips | Ni-NTA HisSorb Plates | Ni-NTA HisSorb Plates, white |
| Form | Transparent strips coated with Ni-NTA |
Transparent 96-well microplates coated with Ni-NTA |
Opaque, white
96-well microplates coated with Ni-NTA |
| Assay suitability | Colorimetric | Colorimetric | Luminescent and fluorescent |
| Binding
capacity per well: |
|||
| Peptides (20每30 amino acids) |
20 pmol | 20 pmol | 20 pmol |
| Proteins | 2每10 pmol | 2每10 pmol | 2每10 pmol |
| Maximum
volume per well |
300 µl | 300 µl | 300 µl |
| Optimal pH | 7.5 | 7.5 | 7.5 |
| Stability | ≡1 year at 20每25∼C | ≡1 year at 20每25∼C | ≡1 year at 20每25∼C |
| Recommended storage | 20每25∼C | 20每25∼C | 20每25∼C |
QIAexpress Detection and Assay Handbook 03/01 (PDF version, 450 KB)