(a) Purified V2A in spray drying buffer or in PBS (phosphate buffer saline) shows identical melting curve (first of two melting transition > 65 °C) in thermal shift assay (b) A pilot-scale spray-dried mixture of Pichia secreted V2A and V3A (equal proportion), showed identical binding activity, before and after drying, to the immobilized antigen in ELISA. Maltodextrin (10%) was used as carrier in the spray-drying run, and also incorporated as negative control in the ELISA. These analysis were repeated twice. (c) Picture of the pilot-scale spray drying installation used, showing bottom 2/3rd of drying chamber and the cyclone (upper right). (d) Sample of the dried powder containing Pichia-secreted mVHH-IgAs.