Trifluoroacetic acid (TFA) is a strong acid, which is commonly used to cleave synthesized peptides from solid-phase resins and is also used to improve HPLC performance in the peptide purification step. Although TFA is important, residual TFA in custom peptides can cause inexplicable discrepancies in subsequent assay data. For instance, TFA in nM concentrations has been shown to interfere with cellular assays, as well as inhibiting cellular proliferation in some instances (Cornish et al.)
In general, most custom peptides are delivered as lyophilized TFA salts, and can contain as much as 10%-45% TFA. To improve the study outcome, TFA exchange is essential before starting your experiment.
GenScript offers two TFA exchange services: Standard Service and Guaranteed Service.
| Service Type | TFA Residue | Salt Type | Report |
|---|---|---|---|
| Guaranteed TFA exchange | <1% | HCl, Formate, Acetate | Included |
| Standard TFA exchange | <10% | HCl, Formate, Acetate, Phosphate | Upon Request* |
In general, the TAT for Guaranteed TFA exchange
service is 8 days,
and 2 days for Standard TFA exchange service.
* If Report is selected for Standard TFA exchange service, extra cost and 1 day will
be
needed.
| Guaranteed TFA Exchange is recommended for: | Standard TFA Exchange is recommended for: |
|---|---|
|
|
To place a quote for TFA exchange service, use our online ordering system. Enter your required peptide sequence, quantity, and purity. In the comments section type "TFA exchange Service" and include your desired salt (HCl, formate, or acetate) and your desired service type (Guaranteed or Standard). Or you can request a quote via email to peptide@genscript.com.
