Blood Blood is the circulatory fluid that runs through most corporeal lifeform s in the universe . Its primary function is to carry nutrients and respiratory gas ses to s and to remove waste products . Blood transfusion s can only be undertaken between individuals with the same blood composition . Many drugs need to be introduced into the bloodstream to take effect . Anesthetic agents , for instance , are intravenously administered . In 2267 , Rigelian scientist s developed a drug that could accelerate the reproduction of blood . ( ) In 2364 , Doctor Beverly Crusher advised Captain Jean - Luc Picard how to use root s as a clotting agent for her bloody wound . ( ) The Klingon spy J ' Dan found a way to smuggle stolen information , encoded in amino acid sequences , in the bloodstream of an unknowing third person . ( ) When experimenting on crewmembers of the , solanogen - based lifeform s slowly turned Lieutenant Edward Hagler ' s blood into a liquid polymer , thereby killing the officer . ( ) Some species did not have blood at all , like the humanoid Breen . ( ) Klingons swore blood oath s as a promise of vengeance , to sanctify various alliances , and as vows by the shedding or mixing of blood . ( ) T ' Pol had Vulcan K - cell s in her blood . These cells stopped her from being infected with a mutagenic virus on the Loque ' eque homeworld in 2153 . ( ) Both Spock and Sarek had type T - negative blood , which was a rare Vulcan type . ( ) As late as 2267 , blood was taken with a needle for medical tests . ( ) Julian Bashir had type B - negative blood . ( ) Odo had type O - negative when he was a humanoid for a short time . ( ) Solbor ' s blood revealed the text of the " Book of the Kosst Amojan " . ( ) Blood chemistry . Blood chemistry is a term used to describe the composition of element s , chemical s , and other substances in an individual ' s blood . The chemistry of the metal - protein complex of the component s responsible for respiratory delivery influence the color of the blood . Known colors and chemical compositions included : It is not known what color blood Gosis ' people had , only that it was not red . It was also not iron - based , though what it was based on is also unknown . ( ) Rigelians were known to share a similar blood chemistry to that of Vulcans . ( ) Acamarian blood was composed of an odd composite of iron and copper - based blood chemistry . ( ) Bolians had a blood chemistry very different from that of other species , especially Vulcans . If a blood transfusion was given from a Vulcan to a Bolian , it would result in the death of the Bolian . There were instances when artificial blood was unavailable and existing blood cells were genetically altered for inter - species transfusions to be successful . ( ) In 2367 , Dr . Beverly Crusher noticed that Lieutenant Commander Susanna Leijten ' s blood chemistry was slightly off after beam ing back from the surface of Tarchannen III . It was later discovered that she was in fact being transformed into another lifeform . ( ) When creating the Jem ' Hadar , the Founder s deliberately omitted a key isogenic enzyme from their blood chemistry , giving it to them in the form of ketracel - white . The Jem ' Hadar needed to keep taking the white or they would die , thus ensuring their loyalty to the Founders . ( ) In 2371 , the ' s EMH , The Doctor , discovered that Ensign Seska ' s blood chemistry was not consistent with that of a Bajoran . Her cover story was that she suffered from Orkett ' s disease as a child during the Occupation of Bajor , and that she had received a bone marrow transplant from a Cardassian woman named Kattell . ( ) After the Borg transplanted skin onto Data ' s arm and the Borg Queen activated his emotion chip , he felt pain when a Borg drone cut this flesh and blood ran out of it . ( ) Appendices . Background information . In , Klingon blood was portrayed as pink and lavender , while in TNG and DS9 it was red . The supposed reason for this is that having floating red blood all over the ship was considered too violent , and would have given the movie a more extreme rating than would be appropriate for the target audience . Pink blood makes it obvious at a glance that the violence is simulated , not real . See here for a more detailed discussion of Klingon blood color . Brown blood – present in Cardassians – is only found in real life in the mollusc " Pinna squamosa " , which is similar to hemocyanin , but is based on manganese , instead of copper . Violet blood – present in Klingons – is found on certain molluscs , which is based on iron , but in a non - heme protein . Unused scripted references . In the second revised final draft script of ( dated ) , Sulu light - heartedly declared , " " I don ' t have a drop of Western blood . " " The final draft script of included an ultimately unused line in which Kirk said to the Onlies , " " Blood . My blood . Are you afraid of it ? Most people are . . . " " In the writers ' first draft script of , the sight of blood , while Doctor Phlox was bandaging a laceration on ' s hand , caused a large , tough - looking engineering officer standing nearby to suddenly faint , so Phlox then switched his focus to the felled giant . Apocrypha . Several non - canon sources have suggested that the bases of blue - blooded aliens ' blood are silicon and cobalt . This would be logical , as some creatures in reality have blue blood based on molecules other than iron and copper .