This is a personalized conjugation kit (PerKit™) to work with any protein with a MW over 20 KDa and for protein labeling of a small molecule containing carboxylic acid (-COOH) functional groups. Using the kit components, the customer converts the carboxylic acid to an activated N-hydroxysuccinimide (NHS) ester, followed by reaction with the surface amino groups of the protein to form a stable amide bond. The final product is desalted to remove any unreacted small molecule acid. 

This kit provides materials to label 15-50 nmole of one protein sample (≥20 KDa)

If you have less than 15 nmole of protein or the MW of protein is less than 20 KDa, you can contact us for a custom conjugation. 
If you would like CellMosaic to perform the conjugation instead, please add PerKit™ Custom Conjugation (AS1002) along with this kit.

Shipping policy: Ship at RT, choose overnight (ships Mon.-Thur.) or 2-day delivery (ships Mon.-Wed.) at checkout.

Requirement for Small Molecule

• Preferably > 90% pure
• Absence of primary or secondary amine (-NH2) groups
• Preferably contains only one non-hindered aliphatic carboxylic acid (-COOH)
• For molecule containing aromatic carboxylic acid, hindered aliphatic carboxylic acid, or hydroxyl (-OH) groups, please consult CellMosaic first before placing the order.

Key Features of this PerKit™

• Offers a simple and easy way to label protein with any small molecule containing carboxylic acid
• Fast and easy preparation: 4 h preparation and <30 minutes hands-on time
• All reagents and supplies included for preparation and purification
• Over 90% pure conjugated products by SEC
• Options to choose tailored services at CellMosaic after conjugation

After conjugation: you can choose to send your sample to CellMosaic for HPLC analysis and calculation of the loading.

Labeling Chemistry

Schematic diagram of the workflow for preparing protein-small molecule conjugates starting with 50 nmole of protein (volume of reagents varies if the amount of protein is < 50 nmole)

Typical Kit Performance Data

SM acid information: 6-carboxyfluorescein (20 µmol)

Protein information: Bovine Serum Albumin (BSA) (50 nmol)

Kit Lot number: 5506.S51207

Figure 1: Size-exclusion HPLC analysis of the purified fluorescein labeled BSA from Step D6 using various amounts of Fluorescein NHS ester. 

Figure 2: UV/Vis spectrum of the purified fluorescein labeled BSA from Step D6 using various amounts of Fluorescein NHS ester. 

Table 1: Summary results of the purity and the average DOL of the fluorescein labeled BSA from Step D6 (Note: Fluorescein is a very hydrophobic compound. A lower DOL was obtained.)