Anti·His HRP Conjugate Kits

The table below lists the epitopes recognized by the Anti-His Conjugates and Anti-His Antibodies. 'H' designates a histidine residue, while 'X' designates any amino acid other than histidine. Note that individual 6xHis-tagged proteins are often recognized better by one Anti-His Antibody than by the others, possibly because of subtle differences in the exact conformation of the 6xHis tag and other parts of the protein in the vicinity of the tag. To choose the optimal antibody for your specific 6xHis-tagged protein and application, QIAGEN offers the Anti-His Antibody Selector Kit. The kit includes 3 µg of each of the three antibodies for direct comparison and economical selection of the one that gives the best results.

Epitopes recognized by QIAexpress Anti-His HRP Conjugates and Anti-His Antibodies

Peptide	Penta-His	Tetra-His	RGS-His
XHHHHHHX	+	+	–
XXHHHHHX	+	+	–
XHXHHHHX	–	+	–
XHHHHXHX	–	+	–
XRGSHHHHX	–	+	+
XRGSHHHHHHX	+	+	+
XHXHHXHX	–	–	–

Note that the presence of specific residues N- or C-terminal to the epitope is not required.

Penta-His and Tetra-His Antibody bind to proteins that have 6xHis tags regardless of the surrounding amino-acids, even when the tag is partially hidden. Subtle differences in the antigen recognition sites of these antibodies mean that some 6xHis-tagged proteins are detected with higher sensitivity by one Anti-His Antibody than by the others (see figure below). Therefore, to achieve optimum results, we recommend comparison of these antibodies in parallel for new applications and proteins. QIAGEN offers the Anti-His Antibody Selector Kit for this purpose.

 

Sensitivity of QIAexpress Anti·His Antibodies

 

Note:  RGS His Antibody regonizes the RGS(His)4 epitope that is found on proteins endcoded by most pQE vectors as well as several pRSETan pBlue BacHis -vectors from Invitrogen.

Insufficient fixation of samples leads to poor morphological preservation. If using methanol or acetone try fixation with paraformaldehyde. If 2% paraformaldehyde is insufficient, increase fixative concentration to 4% and increase incubation time. Keep in mind that too harsh fixation can lead to functional alteration of the 6xHis epitope and loss of recognition by the Anti·His Antibodies.immunofluorescence

Yes, the Blocking Reagent supplied with our Penta-His HRP Conjugate can also be used with other antibodies.