We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is a Blood Culture?

Tricia Christensen
By
Updated May 17, 2024
Our promise to you
WiseGeek is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At WiseGeek, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

A blood culture is part of blood test that can help determine whether a person has bacteria or other infectious agents in his or her bloodstream. Blood cultures may be required when blood infection like septicemia is suspected, or when it’s believed that infection exists in hard to scan areas. For instance if people have bacterial endocarditis, and bacterial matter is not showing up on x-rays or on echocardiograms, doctors might use a blood culture to determine its presence, since some bacteria will spread into the blood stream from the heart.

For people having a blood culture, the procedure is fairly simple, but it does involve at least two blood draws, that are usually drawn from different areas of the body, for example opposite arms. Each arm is swabbed with alcohol to prevent the skin from contaminating the blood sample with normal skin bacteria. The samples taken are then treated specially to see if they will grow bacteria.

This usually means placing the samples in a machine that keeps them at body temperature, so if bacteria is present, it will continue to grow. Samples are then monitored for up to five days to determine if bacteria exist. At the same time, or after a positive blood culture, meaning presence of bacteria, doctors must figure out what type of bacteria is present to determine how best to treat it. They may use a process called subculturing, where they grow bacteria on special plates with agar to determine its type.

Time it takes to determine if a blood culture is positive can vary. Samples may be kept for up to five days to make sure that nothing appears to “grow” in the blood taken. Usually, if bacteria is present in the body, and has been caught in the sample, which isn’t always the case, it takes a couple of days before the blood culture can be determined positive. Sometimes negative blood cultures aren’t accurate, and people may need to have several tests over several days if doctors reasonably suspect bacterial or fungal infection in the blood stream.

There are people who are more likely to have a blood culture performed. Infants and the elderly are more susceptible to blood infections because they have weaker immune systems. Also, those with immunosuppressive diseases like lupus or AIDs might be automatically more suspect of having blood infections if they present with symptoms like high fever, chills, and body aches. However, these symptoms aren’t always indication of blood infection and might instead signal that someone has a nasty virus like the influenza virus. Moreover anyone at any age can develop blood infection.

WiseGeek is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Tricia Christensen
By Tricia Christensen
With a Literature degree from Sonoma State University and years of experience as a WiseGeek contributor, Tricia Christensen is based in Northern California and brings a wealth of knowledge and passion to her writing. Her wide-ranging interests include reading, writing, medicine, art, film, history, politics, ethics, and religion, all of which she incorporates into her informative articles. Tricia is currently working on her first novel.
Discussion Comments
Tricia Christensen
Tricia Christensen
With a Literature degree from Sonoma State University and years of experience as a WiseGeek contributor, Tricia...
Learn more
WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.

WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.