When you choose this add-on option, you will receive 4 identical test tubes of the algal culture media that is currently used to maintain the strain at UTEX. You can determine what media you would be receiving by looking at the media section of the "Algae Details" page for the relevant algal strain. If the strain is maintained on agar, you would receive 4 tubes filled with 10-mL of sterile agar media, already slanted and ready-to-use. These tubes of media can be used to create backup copies in case anything were to happen to the original during experimentation. This is beneficial if you are testing alternate culturing conditions and/or media, since you can recover the strain from the backup instead of having to purchase the strain and wait for it to ship again.

Examples:

1. You want to place an order for UTEX LB 2307 Isochrysis aff. galbana, and UTEX 2 Carteria sp., and you choose the add-on option for the 4 tubes of media for both strains. Since UTEX LB 2307 is a maintained in liquid--as indicated by the 'LB' prefix--you would receive the strains ordered and 4 test tubes of liquid Erdschreiber's Medium. Since UTEX 2 is maintained on an agar slant--as indicated by the lack of a prefix--you would receive 4 test tubes filled with 10-mL agar Proteose Medium.
2.  You want to place an order for UTEX 2714 Chlorella vulgaris with the media add-on option, and UTEX LB 2342 Spirulina maxima without the add-on option. You would receive the strains ordered and 4 test tubes filled with 10-mL agar Proteose Medium (UTEX 2714) only.