Why Blood Plasma Isn’t Always Yellow

July 30, 2020

Plasma is a protein-rich component of blood that helps your body defend itself against infections. It is used to treat a host of rare diseases and is often described as being “yellow”, “gold” or “straw-coloured”, but that isn’t always the case. A number of factors can cause plasma to become discoloured and/or cloudy, which can affect the viability of a donation. 

In today’s blog, we’ll be exploring the reasons why blood plasma isn’t always yellow. 

Why Is Plasma Yellow?

Before we get into all the reasons behind discoloured plasma, it’s important to first establish why plasma is supposed to be yellow. The reason plasma is typically yellow in colour and not red like our blood is due to a pigment called bilirubin. Bilirubin is the end product of red blood cell (haemoglobin) breakdown. It is circulated in your blood then travels to your liver where it is processed and eventually removed. Higher bilirubin values cause a stronger yellow blood plasma colour.

Other bodily components that contribute to plasma’s yellow hue are carotenoids, which are pigments commonly found in fruits and vegetables like carrots, and haemoglobin, a protein found in red blood cells.

Causes of Plasma Discolouration

Common hues that are seen when plasma becomes discoloured are reddish-orange and green. Reddish-orange plasma is usually caused by red blood cells that have ruptured and decomposed, which is a process known as haemolysis. Smokers are more prone to having reddish-orange plasma due to the contaminated lack of oxygen in their system. Unfortunately, plasma that is too red cannot be used.

Green plasma, on the other hand, has been attributed to elevated levels of a copper-containing pigment called ceruloplasmin. Hormonal medications, like the pill, can cause higher levels of ceruloplasmin in the body. Infections and medical dyes used in diagnostic procedures can also cause green plasma.  

Causes of Cloudy Plasma

In addition to being reddish-orange and green, plasma can also sometimes be milky white and cloudy. This phenomenon, known as lipemia, occurs when a donor has consumed fatty food prior to donating. Cloudy blood plasma cannot be used to manufacture plasma products. 

How to Improve the Quality of Your Plasma

As a plasma donor, there are a few things you can do to help make sure your plasma is the best possible quality. We recommend that donors refrain from smoking at least 8 hours prior to plasma donation. Donors should also avoid eating fatty foods like potato chips, pizza, peanut butter, and French fries before donating.

At Canadian Plasma Resources, our goal is to safely contribute to the creation of as many life-saving therapies as possible. We measure each and every plasma unit we collect against a colour chart to ensure they meet manufacturing requirements. Book your next appointment today to help us help patients in need.