All small peptides/haptens must be coupled to a carrier protein (KLH or Keyhole limpet hemocyanin, BSA, Ovalbumin, etc) in order to elicit high titer antibodies. Generally, peptides can be coupled to other proteins by utilizing:
2. A free Cysteine group (available as part of the sequence or added at the N or c-terminus)-preferred method of coupling peptides.
Chemical conjugation using Cysteine offers a single point attachment provided there is just one Cys in the sequence (added or part of the native sequence). It is preferable to add Cys at the NH2 terminus if the peptide is internal or it represents the very C-terminus. This will keep the COOH free (non-conjugated) as it exists in native protein. For peptides representing the very NH2-terminal sequences, Cys should be added at the C-terminus of the peptide. For internal peptides, Cys can be added at either end but it is easier to synthesize peptides containing a NH2-terminal Cysteine
We use MBS (m-Maleimidobenzoyl-N-hydroxysuccinimide Ester) method for peptides containing Cysteine. Glutraldehyde method is used coupling via the free amino group and EDAC (1-Ethyl-3-(3′-dimethylaminopropyl)carbodiimide) for free COOH.
Cat # CONJ-1, Custom conjugation of peptide to KLH/BSA/Ovalbumin, $195 per peptide (couple ~2-5 mg peptide)
Time ~2-3 working days.
Pre-Activated BSA and KLH peptide/Protein Conjugation Kits:
BSA and KLH proteins are pre-activated with MBS and supplied in powder form. All other necessary buffers are provided for coupling 2-4 mg of the peptide in about 3-4 hrs at room temp. The conjugated peptides are ready for immunization. Each kit contains 2x 2 mg of the pre-activated proteins (BSA or KLH) and other buffers to couple 2 different peptides. Easy to follow directions are provided with the kit.
Cat # BSAX200, Peptide/Protein conjugation to Pre-activated BSA Kit, $195 (sufficient for 2 peptides).
Coupling of peptides or proteins to Agarose (affinity matrix):
Cysteine can also be used to couple peptides to Sepharose for affinity purification of antibodies. Amino or COOH-conjugation chemistries should be avoided as most peptides contains several NH2 and COOH groups available in a given peptide sequence resulting into multi-point attachment and peptide distortion.
Cat # AFFI-2, Custom conjugation of peptide to agarose, $295 per peptide (couple ~2-5 mg peptide)
Affinity matrix is supplied in a ready-to-use mini column.
We also offer complete affinity purification package Cat # AFFI-I for the preparation of affinity matrix, purification of antibodies, and ELISA testing.
This package typically includes: Coupling of peptide/proteins (up to 2-5 mg peptide to Agarose), purification of any 1 bleed or ~ 15 ml antiserum; ELISA testing of both unpurified and affinity pure antibodies, and supply of affinity column. We also monitor the antibody activity in the unbound fraction to make sure antibodies are not overloaded and wasted.
Time 3-5 working days. You may contact us or E-mail Us if you should have any questions or you would like to make a purchase. If you need any technical info on our products or have a question, please do not hesitate to call us or send us an email. Should you’ve any problems with our product, Please send us an email or call us during work hours, Thank You.