Venipuncture is the process through which Phlebotomists gain access to the veins and take samples from venous blood.  There are some special tools that can be used to make this process easier both in the laboratory and out in the field. A part of your phlebotomy training is to understand the ins and outs of how to use these items.


Sometimes it is difficult for phlebotomists to find a vein from which to gather their samples. For instances such as these, phlebotomists can turn to trans-illumination devices. Basically trans-illuminators are machines that are able to shine LED or infrared light into the skin. The light is actually absorbed by the blood’s hemoglobin. These machines make the veins visible to the eye as dark lines and the phlebotomist is able to find a vein from which to draw blood.

There are a number of trans-illuminators available on the market such as the Venoscope II, the Neonatal trans-illuminator and the Accuvein AV 300.


A tourniquet is a device that is used to restrict the flow of blood by compressing a blood vessel. These are the things that we often see in action or war movies when a character is bleeding heavily from a gunshot, knife or sword wound. Something must be tied tightly around the wound in order to stem the flow of blood. If the blood flow is restricted, a person will bleed much slower and it gives other people more time to get help for the injured person. You can make a tourniquet by tying cloth or another object around a bleeding wound.  In the films we usually see tourniquets made from torn shirts or belts.

In phlebotomy, you must make sure the tourniquet is tight but not too tight. The objective is to restrict venous blood flow but to allow arterial blood flow.  When a tourniquet is applied correctly it actually enlarges the veins. This makes them easier for a phlebotomist to find. It is also easier to pierce enlarged veins with a needle.

It’s important to make sure that a tourniquet is applied in a way in which it is easy to release with one hand. This is essential because if blood flow is restricted for more than 1 minute, blood components can be altered.

Thankfully, there are a lot of different types of tourniquets aside from torn shirts and belts! They come in both child and adult sizes. Strap tourniquets are the most common type used. They can be made of latex, vinyl or other cheap, flexible material.

Some tourniquets can be used more than once, but they must be discarded or thrown away if they become contaminated by blood or if they are dropped. This is because we don’t want to pass infections onto patients.

It is not currently a requirement to dispose of tourniquets after a single use; however, many institutions have instituted this policy. One of the main reasons for this procedure is to prevent the spread of MRSA, commonly known as a staph infection. Studies have shown, however, that it is also very likely for infections to be passed to tourniquets and subsequently on to the patient from phlebotomists’ hands. So please remember to wash your hands thoroughly before applying a tourniquet!

Other equipment

Needles are also obviously needed to gather samples from venous blood. Most blood procedures are gathered from needles gauged between 20 and 23 with a 21 gauge being the most common.