The fingerstick device should be held firmly against the puncture site. To obtain the best capillary specimen using the finger, align the puncture device perpendicular (horizontal) to the whorls of the fingerprint. This cross-cut of the fingerprint whorls causes the blood to bead at the puncture site, allowing the phlebotomist to efficiently collect the drops of blood into the container. This image illustrates the correct position of the cut in relation to the fingerprint lines. Show
If the puncture is made parallel to the fingerprint whorls (as shown below), the blood will not bead, but rather it will travel down the channels between the lines of the fingerprint. This makes it difficult to collect the blood into the container. The phlebotomist may inadvertently "scrape" the blood from the skin while filling the container, resulting in hemolysis and/or clotting of the specimen. The tip of the finger should be avoided. Puncturing the fingertip may cause unnecessary discomfort to the patient. You are here: Geisinger Medical Laboratories > Specimen Collection Manual and Test Catalog > Blood Specimen Collection and ProcessingThe first step in acquiring a quality lab test result for any patient is the specimen collection procedure. The venipuncture procedure is complex, requiring both knowledge and skill to perform. Several essential steps are required for every successful collection procedure: Venipuncture Procedure:
Fingerstick Procedure:
Heelstick Procedure (infants):The recommended location for blood collection on a newborn baby or infant is the heel. The diagram below indicates the proper area to use for heel punctures for blood collection.
Order of Draw:Blood collection tubes must be drawn in a specific order to avoid cross-contamination of additives between tubes. The recommended order of draw is:
Labeling The SampleAll specimens must be received by the laboratory with a legible label containing at least two (2) unique identifiers. The specimen must be labeled with the patient's full name (preferably last name first, then first name last) and one of the following:
Areas to Avoid When Choosing a Site for Blood Draw:Certain areas are to be avoided when choosing a site for blood draw:
Techniques to Prevent Hemolysis (which can interfere with many tests):
Blood Sample Handling and Processing:Pre-centrifugation Handling - The first critical step in the lab testing process, after obtaining the sample, is the preparation of the blood samples. Specimen integrity can be maintained by following some basic handling processes:
Where should the Lancet be placed when performing a capillary puncture?The index finger can be calloused or sensitive and the little finger does not have enough tissue to prevent hitting the bone with the lancet. The puncture is done to the left or right of the midline of the palmar surface of the fingertip, staying away from the fingernail.
What is the proper technique for capillary puncture?The puncture must be on the palm-up surface of the distal segment (fingertip) of the middle or ring finger (a). The puncture should be made across the fingerprint, not parallel to it (b). The puncture must be performed on the side of the fingertip where tissue depth is sufficient to prevent bone injury.
Which of the following tubes should the phlebotomist draw first for a capillary collection?CLSI recommends the following order of draw for skin puncture: Blood gases, EDTA tubes, Other additive tubes, then Serum tubes. The correct order of draw would be: two light blue top tubes (one waste and one for PT which is a coagulation test), green top tube (for the Chem 7), and the lavender top tube (for the CBC).
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