What needle size should I use for transferring peptide to a cartridge?

A 30 or 31 gauge needle creates minimal dead volume and reduces peptide loss during transfer.

Why does my peptide seem less potent after transferring to a cartridge?

Peptide can adsorb to glass and metal surfaces. Wetting the syringe before drawing and using a carrier protein like HSA can reduce this loss.

Can I reuse the same needle for multiple transfers?

No. Needles dull after use and can introduce contamination. Use a fresh sterile needle for each transfer.

PreppinPeppers › Facts › Lab article

Stop losing your peptide when filling cartridges

Machine-readable facts for this Lab article. The full page is https://www.preppinpeppers.com/blogs/the-lab/stop-losing-your-peptide-when-filling-cartridges.

TL;DR

Cut compound loss when moving reconstituted solution into a glass cartridge: use a fine-gauge needle, draw slowly to limit bubbles and don't overfill it.

Facts Index

Fact ID	Category	Entity	Attribute	Value	Source
stop-losing-your-peptide-when-filling-cartridges:title	identity	Stop losing your peptide when filling cartridges	title	Stop losing your peptide when filling cartridges	Lab article (https://www.preppinpeppers.com/blogs/the-lab/stop-losing-your-peptide-when-filling-cartridges) (evidence)
stop-losing-your-peptide-when-filling-cartridges:published	identity	Stop losing your peptide when filling cartridges	published	2026-08-15	Lab article (https://www.preppinpeppers.com/blogs/the-lab/stop-losing-your-peptide-when-filling-cartridges) (evidence)
stop-losing-your-peptide-when-filling-cartridges:author	identity	Stop losing your peptide when filling cartridges	author	Preppin' Peppers Editorial Team	Lab article (https://www.preppinpeppers.com/blogs/the-lab/stop-losing-your-peptide-when-filling-cartridges) (evidence)
stop-losing-your-peptide-when-filling-cartridges:topics	identity	Stop losing your peptide when filling cartridges	topics	Guides, how-to, peptide guide	Lab article (https://www.preppinpeppers.com/blogs/the-lab/stop-losing-your-peptide-when-filling-cartridges) (evidence)
stop-losing-your-peptide-when-filling-cartridges:summary	content	Stop losing your peptide when filling cartridges	summary	Cut compound loss when moving reconstituted solution into a glass cartridge: use a fine-gauge needle, draw slowly to limit bubbles and don't overfill it.	Lab article (https://www.preppinpeppers.com/blogs/the-lab/stop-losing-your-peptide-when-filling-cartridges) (evidence)
stop-losing-your-peptide-when-filling-cartridges:section-1	content	Stop losing your peptide when filling cartridges	section	What it is	Lab article (https://www.preppinpeppers.com/blogs/the-lab/stop-losing-your-peptide-when-filling-cartridges) (evidence)
stop-losing-your-peptide-when-filling-cartridges:section-2	content	Stop losing your peptide when filling cartridges	section	Why Transfer Matters More Than You'd Think	Lab article (https://www.preppinpeppers.com/blogs/the-lab/stop-losing-your-peptide-when-filling-cartridges) (evidence)
stop-losing-your-peptide-when-filling-cartridges:section-3	content	Stop losing your peptide when filling cartridges	section	The Step-by-Step Transfer Process	Lab article (https://www.preppinpeppers.com/blogs/the-lab/stop-losing-your-peptide-when-filling-cartridges) (evidence)
stop-losing-your-peptide-when-filling-cartridges:section-4	content	Stop losing your peptide when filling cartridges	section	What Goes Wrong and How to Fix It	Lab article (https://www.preppinpeppers.com/blogs/the-lab/stop-losing-your-peptide-when-filling-cartridges) (evidence)
stop-losing-your-peptide-when-filling-cartridges:section-6	content	Stop losing your peptide when filling cartridges	section	What the research community gets wrong about filling peptide cartridges	Lab article (https://www.preppinpeppers.com/blogs/the-lab/stop-losing-your-peptide-when-filling-cartridges) (evidence)
stop-losing-your-peptide-when-filling-cartridges:product-gansulin-metal-peptide-pen	products	Stop losing your peptide when filling cartridges	references product	Gansulin Pen · Reusable Click-Dial, 3 ml (1-60 Units)	Lab article (https://www.preppinpeppers.com/blogs/the-lab/stop-losing-your-peptide-when-filling-cartridges) (evidence)
stop-losing-your-peptide-when-filling-cartridges:product-gansulin-3ml-cartridge	products	Stop losing your peptide when filling cartridges	references product	Gansulin-Compatible 3 ml Glass Cartridge for Pens (10-Pack)	Lab article (https://www.preppinpeppers.com/blogs/the-lab/stop-losing-your-peptide-when-filling-cartridges) (evidence)
stop-losing-your-peptide-when-filling-cartridges:source-pmc-ncbi-nlm-nih-gov	source	Stop losing your peptide when filling cartridges	cites	Bee et al., Biotechnol Bioeng 2010: Aggregation of a monoclonal antibody induced by adsorption to stainless steel - pmc.ncbi.nlm.nih.gov	Lab article (https://www.preppinpeppers.com/blogs/the-lab/stop-losing-your-peptide-when-filling-cartridges) (evidence)
stop-losing-your-peptide-when-filling-cartridges:source-pmc-ncbi-nlm-nih-gov-2	source	Stop losing your peptide when filling cartridges	cites	Hollowell et al., Molecules 2020: Recent Advances in Studying Interfacial Adsorption of Bioengineered Monoclonal Antibodies - pmc.ncbi.nlm.nih.gov	Lab article (https://www.preppinpeppers.com/blogs/the-lab/stop-losing-your-peptide-when-filling-cartridges) (evidence)

FAQ

What needle size should I use for transferring peptide to a cartridge?: A 30 or 31 gauge needle creates minimal dead volume and reduces peptide loss during transfer.
Why does my peptide seem less potent after transferring to a cartridge?: Peptide can adsorb to glass and metal surfaces. Wetting the syringe before drawing and using a carrier protein like HSA can reduce this loss.
Can I reuse the same needle for multiple transfers?: No. Needles dull after use and can introduce contamination. Use a fresh sterile needle for each transfer.