5 Common Lab Mistakes When Handling Peptides (And How to Avoid Them)

Why this matters

Peptides are often delicate and pricey. Small mistakes can reduce yield, alter experimental results, or require re-ordering materials. Below are five mistakes we see frequently and simple steps to prevent them.

1. Shaking Vials After Reconstitution

The mistake: Vigorously shaking peptide vials to dissolve powder quickly.

Why it's a problem: Aggressive shaking can cause foaming, shear forces, or degradation of sensitive peptides, reducing activity or purity.

Fix: Inject solvent slowly against the glass wall and gently swirl the vial until fully dissolved. If a tendon-like pellet remains, let it sit; do not rub or vortex.

2. Using the Wrong Needle or Syringe Size

The mistake: Choosing a large-gauge needle or oversized syringe for small volumes.

Why it's a problem: Thicker needles and larger syringes reduce dosing accuracy, increase solution loss, and may damage vial septa.

Fix: Use a 1 mL or 3 mL syringe for small volumes, and 27G–30G needles for routine reconstitution and transfers. For micro-volumes, consider insulin-style syringes.

3. Not Accounting for Units and Conversions

The mistake: Misreading units (mL vs µL, mg vs µg) or skipping conversion steps.

Why it's a problem: Unit errors can cause 10×–1000× mistakes, wasting material and compromising experiments.

Fix: Always write units clearly, show your math, and use the smallest appropriate device for accuracy (e.g., 1 mL syringe for 0.2 mL). Consider adding an interactive conversion widget to your digital protocols.

4. Reusing Needles or Improper Disposal

The mistake: Reusing needles between vials or failing to dispose of sharps properly.

Why it's a problem: Reuse risks contamination and cross-sample interference. Improper disposal is an occupational safety hazard.

Fix: Use a new sterile needle for each vial or critical transfer. Immediately dispose of used needles in a labeled sharps container. If your protocol requires a capped needle for future use, follow your institutional SOPs.

5. Ignoring Storage and Temperature Recommendations

The mistake: Leaving reconstituted peptides at room temperature or storing lyophilized peptides incorrectly.

Why it's a problem: Many peptides degrade faster at higher temperatures or when exposed to light and moisture.

Fix: Follow the manufacturer's storage instructions: lyophilized peptides are often stored at –20°C or –80°C, while reconstituted solutions may require refrigeration and use within a specified time. Label vials with date/time and initials.

Final thoughts

Small changes in technique can improve reproducibility, safety, and cost-efficiency.