fractions were fixed and double stained for insulin and glucagon (both
fractions), insulin and somatostatin (pull-down fraction) or glucagon and
somatostatin (flow-through fraction). Primary antibodies used were guinea
pig anti-insulin (Fitzgerald #20-IP35, 1:1000), rabbit anti-glucagon (Cell
Signaling #2760, 1:200), and mouse anti-somatostatin (Santa Cruz sc-55565,
1:100). Secondary antibodies used were goat anti-rabbit Alexa Fluor 488
conjugate (Cell Signaling #4412, 1:500), Cy3 AffinityPure donkey anti-guinea
pig (Jackson ImmunoResearch #706–165–148, 1:500), goat
anti-mouse Alexa Fluor Plus 488 conjugate (Thermofisher A32723, 1:500), goat
anti-mouse Alexa Fluor 594 Affinity Pure conjugate (Jackson ImmunoResearch
#115–585–020, 1:500).