Ordering information
Name	Cat. No.	Vol.	Scheme
G-CHO	PMG040-2	2 ml

1. Overview

PuriMag™ G-CHO, Aldehyde-Functionalized Magnetic Nanoparticles are uniform, polymer-coated superparamagnetic nanoparticles. Their hydrophilic surface ensures excellent dispersibility, low non-specific adsorption, and easy handling in diverse buffers. The high-density aldehyde functional groups enable permanent covalent coupling with primary amine-containing ligands.PuriMag™ G-CHO beads are optimal for conjugating proteins and small peptides, including enzymes, antibodies, and amine-modified nucleic acids. They are suitable for magnetic separation applications such as: Affinity enrichment; Protein purification; Immunoprecipitation; Cell sorting.

Features & Advantages:
        Broad Coupling Conditions: Efficient conjugation at pH 4–10, 4–25°C, for 2–16 h
        Solvent Compatibility: Water-insoluble ligands can be coupled in:Organic solvents (10–30% acetone, dioxane, alcohols, DMF, DMSO)Denaturants (6 M guanidine HCl or 4 M urea in coupling buffer) 

        Stable covalent bonds with minimal ligand leakage

        Generates reusable immunoaffinity matrices

        Low non-specific binding

        Immobilization capacity: 1–50 mg protein or 0.1–5 mg peptide per gram beads

        Applications: Antibody/protein/peptide/DNA/RNA purification; cell sorting; immunoprecipitation    

        Convenient and rapid coupling

Coupling Mechanism:

2. product description

Product Specifications
Description	Polymer coated Fe3O4 nanoparticles
Particle Size	200 nm
Number of Beads	~1.7×1010 beads/mg
Matrix	Proprietary polymer
Functional group	Aldehyde group
Group density	~300 µmole / g of Beads
Magnetization	60~70 EMU/g
Formulation	10 mg/ml suspension in DI water
Stability	pH 3.5~10, 4~80 ℃, most organic solvents
Storage	1 year at 4~8 ℃. Do not freeze.

3. Instructions for Use

Note: The following protocol exemplifies coupling proteins and/or peptides to PuriMag™ Aldehyde-Activated Magnetic Nanoparticles.
Optimization of bead quantity is strongly recommended. Insufficient ligand loading may increase non-specific binding, while excessive loading may cause steric hindrance. For affinity matrices, use 1–50 mg protein or 0.1–5 mg peptide per gram beads. Scale proportionally as needed.

A. Required Materials

    1.Magnetic Racks:

        For 12×1.5–2 mL tubes (Mrack02)

        For 2×50 mL or 2×15 mL tubes (Mrack03)

    2.Coupling Buffers:

        Soluble Ligands: 0.1 M Sodium Phosphate, pH 7.0

        Insoluble Ligands: 0.1 M Sodium Phosphate, pH 7.0, containing:

        10–30% acetone, or dioxane, or alcohols, or DMF, or DMSO, or

        6 M Guanidine•HCl or 4 M Urea

        Note: Minimal ionic strength is critical. Avoid amine-containing buffers (e.g., Tris) or nucleophiles. Storage/wash buffers may contain amines. Prepare sodium cyanoborohydride in a chemical fume hood due to high toxicity.

    3.Blocking Buffer: 1 M Tris•HCl, 0.05% NaN₃, pH 7.4

    4.Wash Buffer: 1 M NaCl, 0.05% NaN₃

    5.Reducing Agent: 5 M Sodium Cyanoborohydride (NaCNBH₃ in 1 M NaOH)

B. Bead Preparation
*Note: PuriMag™ Aldehyde Beads are supplied as 10 mg/mL suspension in water. Store at 4°C. Vortex thoroughly before use.*

    1.Transfer 2 mg beads to a microcentrifuge tube.

    2.Place tube on magnetic stand for 1 min. Discard supernatant. Resuspend beads in 50 μL coupling buffer.

    3.Repeat Step 2 three times (total 4 washes).

        *Note: Use hydrated beads immediately due to functional group instability.*

C. Protein Coupling

    1.Dissolve 50–200 μg protein/peptide in 100 μL coupling buffer (soluble or insoluble formulation per ligand solubility). If pre-suspended in other buffers, dilute with 4× volume coupling buffer or perform desalting/dialysis.

        *Note: Optimize ligand concentration empirically. Recommended: 0.5–10 mg/mL for proteins; >200 μmol/mL for small peptides.*

    2.In fume hood: Add protein solution and 1 μL NaCNBH₃ solution (10 μL/mL total volume → 50 mM final) to beads. Resuspend and mix by pipetting. Incubate with rotation overnight at RT or 4°C.

    3.Wash beads 3× with 1 mL coupling buffer (as in Step B2).

    4.Add 0.1–0.5 mL blocking buffer + 0.5–1 μL NaCNBH₃ (10 μL/mL total volume → 50 mM final). Incubate 1 h at RT or overnight at 4°C.

    5.Wash beads 4–6× with 1 mL wash buffer (as in Step 2).

    6.Resuspend in PBS with 0.1% NaN₃ (w/v). Store at 4°C (avoid freezing).

D. General Affinity Purification Protocol
Note: While nucleic acid purification is standardized, protein purification requires target-specific optimization.

    1.Transfer optimized bead amount to tube. Separate magnetically (1–3 min), discard supernatant.

        *Note: Titrate beads against target abundance. Typical binding: 1–20 μg target protein per mg beads.*

    2.Wash beads 3× with 5 bead volumes PBS (30 sec resuspension per wash).

    3.Incubate beads with crude sample (1–2 h at RT or optimized temperature).

    4.Wash with PBS or 1M NaCl until eluate OD₂₈₀ < 0.05.

    5.Elute target using:

        Low pH (2–4)

        High pH (10–12)

        High salt

        Heat

        Affinity elution

        Boiling in SDS-PAGE buffer

            (For research use only!)