1. General principles
a. Antibodies are precious resources and must be conserved—i.e., use as little as possible, do not waste, and keep cold.
b. Antibodies are proteins and should be kept cold (refrigerated, on ice, or frozen) when not in use.
c. The more dilute the antibody is, the less stable. Therefore, store antibodies in concentrated form without dilution.
d. Companies that supply antibodies generally also supply instructions on storage and handling. Read and follow the instructions.
e. Antibodies work best when freshly diluted. Do not dilute your antibodies to make working solutions for immunostaining until you’re ready to start the incubations.
f. Repeated freezing and thawing kills antibodies. Once you have thawed an antibody solution, thereafter store it at 4°C (unless you are aliquoting a newly arrived antibody; see next section).
2. What to do with newly arrived antibodies: ALIQUOT!
a. If the antibody arrives frozen, thaw it and place on ice. If it arrives in liquid form, immediately place it on ice. Vortex gently to mix, and spin briefly in microcentrifuge to collect all liquid at bottom of tube.
b. Gently vortex the antibody solution to mix, and spin briefly in microcentrifuge to collect all liquid at bottom of tube.
c. Estimate the total volume of the antibody solution, and how many aliquots you want to make. Typically, aliquots of 10-50 ml are appropriate (larger aliquots for antibodies that are used with relatively little dilution, e.g. 1:10; and smaller aliquots for antibodies that will be highly diluted, e.g. 1:5000).
d. Label 500 ml tubes with the antibody name, the dilution, and the date aliquoted; e.g., anti–calretinin, undiluted, 3/6/02.
e. Aliquot the antibody into the tubes. Put the tubes in a box in the freezer, and make sure the box is appropriately labeled (e.g., Hevner lab polyclonal antibodies).
f. Enter the antibody in our computer database. Put any accompanying literature or instructions in our antibody notebook.
g. If you thaw an antibody, write the thaw date on the tube; e.g., thaw 3/8/02.
3. Preparing antibodies for immunohistochemistry
a. Use thawed antibody stocks first, but only if less than 3-6 months old.
b. If you need more antibody, thaw a new aliquot, write the thaw date on the tube, and thereafter store in the refrig. (i.e., do not re-freeze).