"Rabbit Plasma, Non-Sterile, with Sodium Citrate, Young" answers four questions before you've opened the datasheet. Plasma listings are terse because every word in them is a specification. This is what each one commits us to, and how to read them when you're choosing between two similar items.
Species and age
The species sets the protein composition and the antibody background. Rabbit plasma is the standard research matrix, bovine and porcine are used where volume or a livestock model matters, and chicken plasma is the choice for avian assays. "Young" or "mature" is the age class of the animals, which affects hormone levels, antibody titers and lipid content. When the plasma is just a background matrix, age class is a consistency choice. When the animal's physiology is part of the experiment, it's a variable you need to specify.
Anticoagulant
Plasma exists because an anticoagulant was in the collection bag, and that chemical is a permanent part of the product. Sodium citrate is required for coagulation work, EDTA for hematology and nucleic acids, heparin for chemistry and enzyme assays, and ACD where the cells need to survive storage. The full comparison is in choosing the right anticoagulant for plasma. The short version: match the anticoagulant to the downstream assay before you look at anything else.
Sterile or non-sterile
Non-sterile plasma, such as rabbit plasma with sodium citrate, is collected cleanly but not filtered. It's the economical choice for assays that run in hours: coagulation tests, immunoassay matrices, protein purification starting material. Sterile-filtered plasma has been passed through a 0.2 µm filter into sterile containers and culture tested. You need it for cell culture, for any incubation longer than a working day, and for reagents that will be stored liquid. Filtration adds cost, so we list both rather than filter everything. Sterility as a manufacturing control is part of good practice for biological products in general (WHO). For a research plasma the question is simpler: would your assay notice a stray organism?
Hemolysis grade
Red cells that rupture during collection release hemoglobin and the plasma turns pink to red. Hemolysis interferes with optical readings and with some enzyme assays, so listings carry a grade: non-hemolyzed, trace hemolyzed, or hemolyzed. Optical and enzymatic assays want non-hemolyzed. For protein purification or antibody adsorption, trace hemolysis does no harm and costs less.
Storage and thawing
Research plasma ships frozen on dry ice and should be stored at −20 °C or colder, or −70 °C for coagulation work, where the labile factors V and VIII decline fastest. Thaw once, in a 37 °C bath just until liquid or overnight at 4 °C, mix gently, and aliquot whatever you won't use. Cryoprecipitate that forms on slow thawing is fibrinogen and redissolves if you warm it to 37 °C. Refrigerated storage is only for fresh plasma that will be used within days.
Because we collect from our own rabbits and from other species on a schedule, a plasma that doesn't appear in the catalog, a different anticoagulant concentration, a sterile version of a non-sterile item, a specific age class, is a matter of setting up the draw. Tell us the specification and we'll quote it.