Product manual
Product use, preparation, operating conditions and storage.
Linkers and crosslinkersCrosslinking reagent
SPDP Crosslinkers
Cat. No.QH-70-7007
Connect primary amines and free thiols through NHS and pyridyl-disulfide groups, forming a reducible linkage.
Packs & quoteDefine the sequence
Validate at small scale
Separate and proceed
Product formNHS Ester/Pyridyldithiol
TargetPrimary amines and free thiols
Preparation and storage
- Storage
- Store at -20°C, protect from light and moisture
Reactive ends and coupling route
NHS first couples to an amine, then pyridyl disulfide undergoes exchange with a thiol to form a disulfide. The linkage is reduction-sensitive and differs from SMCC coupling.
Sequential bioconjugation
Connect primary amines and free thiols through NHS and pyridyl-disulfide groups, forming a reducible linkage.
Product and functional assessment
Analyze conjugation and compare stability under relevant reducing and nonreducing conditions.
Specifications
Product information
- Product name
- SPDP Crosslinkers
- Cat. No.
- QH-70-7007
- Product form
- NHS Ester/Pyridyldithiol
- Target
- Primary amines and free thiols
- Pack sizes
- 50 mg / 100 mg / 250 mg
Preparation and properties
- CAS
- 68181-17-9
- Storage
- Store at -20°C, protect from light and moisture
Product parameters
Use parameters for the exact catalog number when preparing reagents, setting reagent input or calculating results. Request a lot-specific CoA for test results.
Protocol
Pre-reaction checks
Exclude residual components that reduce disulfides or compete for thiols during coupling.
Solvent and molar calculation
Select solvent for this structure, salt form and solubility. Calculate molar inputs from its molecular weight; equal masses of different linkers are not equimolar.
Define the sequence
Confirm the first target group and subsequent partner, then set input, pH, temperature and time for this reagent.
Validate at small scale
Exclude residual components that reduce disulfides or compete for thiols during coupling.
Separate and proceed
Remove free reagents that interfere with the next step, retain the desired handle and complete the planned pairing.
Assess the outcome
Analyze conjugation and compare stability under relevant reducing and nonreducing conditions.
Request product documentation
Select a document and enter your phone and email. Include the lot number for a CoA.
SPDP CrosslinkersQH-70-7007
Certificate of analysis (CoA)
Lot-specific test results. Include the lot number from the vial.
Safety data sheet (SDS)
Handling, storage and emergency response information.
Quality and lot information
Untreated sample
Compare integrity and function with an untreated aliquot from the same preparation.
Reaction-pair control
Omit activation or a paired component to assess adsorption, residual reagents and nonspecific reaction.
References
Thermo Fisher · Amine-reactive chemistry
thermofisher.com
Distinguishes amine-reactive forms such as NHS and isothiocyanate and competing buffers; separately establish whether a nucleic-acid sample has accessible amines.
Thermo Fisher · Sulfhydryl-reactive chemistry
thermofisher.com
Explains thiol addition, blocking and disulfide exchange; maleimide, NEM, SPDP and Traut’s reagent have different purposes and products.
Frequently asked questions
How do this reagent’s handles participate in coupling?
NHS first couples to an amine, then pyridyl disulfide undergoes exchange with a thiol to form a disulfide. The linkage is reduction-sensitive and differs from SMCC coupling.
Does this reagent itself provide fluorescence?
It is used for coupling, modification, blocking or biotin deposition. Fluorescence requires a suitable fluorophore or detection system.
Can another linker’s conditions be reused?
Reactive ends, spacers, salt form and solubility can differ. Establish a small-scale reaction with this reagent and analyze the product.
How is the intended outcome confirmed?
Analyze conjugation and compare stability under relevant reducing and nonreducing conditions.