Table 5.

Components and instructions for preparation of 0.5% alginate and calcium solution used for crosslinking

	Component	Catalog no.	Supplier	Final concentration
0.5% Alginate	Sterile PBS (−/−) Alginic acid sodium salt	14190-144 71238	Gibco Sigma Aldrich	Base 0.5%
• Typical volume prepared: 20 mL
• Shelf life: 1 month at 4 °C
• Sterile filter PBS into a 50 mL conical tube and add alginate to the top of the solution. Place on shaker at 4 °C overnight to dissolve.
Calcium solution	Sterile MilliQ H2O			Base
	CaCl2	C5670	Sigma Aldrich	50 mM
	NaCl	S5886	Sigma Aldrich	140 mM
• Typical volume prepared: 500 mL
• Shelf life: Indefinite at room temperature
• Combine components and mix on a stir plate until dissolved, then sterile filter.