Every blood tube needs a label applied directly at the bedside, immediately after the draw, with at least two unique patient identifiers. Getting this right is straightforward once you know the placement rules, the required information, and the mistakes that get specimens rejected. Here’s how to do it correctly every time.
What Goes on the Label
Safety standards require at least two unique patient identifiers on every tube. In practice, most facilities use three: the patient’s full name, date of birth, and a medical record number. The label also needs the date and time of collection, the collector’s initials or ID, and often the specimen type or test being ordered. Some facilities add the patient’s location (room number, clinic name) as well.
The key word is “unique.” A room number alone doesn’t count as an identifier because it can change. The identifiers must be tied specifically to that patient, so name plus date of birth plus medical record number is the standard combination. Before you even uncap a needle, verbally confirm these identifiers with the patient by asking them to state their name and birthdate rather than reading it to them and asking them to confirm.
Where to Place the Label on the Tube
Stick the label lengthwise along the tube, starting directly under the cap and running downward over the manufacturer’s printed label. Orient it so the patient’s name faces upward when the tube is standing in a rack. This positioning matters because the tube cap color tells the lab which additive is inside, and the label shouldn’t cover it.
Leave a visible strip along the opposite side of the tube so the contents can be seen through the glass or plastic. This “viewing window” lets lab staff check for problems like clotting, hemolysis (when red blood cells break open and turn the sample pink or red), or an inadequate fill level, all without peeling anything off. If your label wraps entirely around the tube, the lab may not be able to assess the specimen visually before processing it.
If your facility uses barcode labels, orient them vertically so the barcode lines look like a ladder when the tube is standing upright. This alignment lets automated lab scanners read the code as tubes move through analyzers on a track. A horizontally oriented barcode can cause read failures and processing delays.
Label at the Bedside, Not Before
The single most important rule in tube labeling is this: label the tube at the patient’s side, right after drawing the blood, before you leave the room. Never pre-label tubes before the draw. Pre-labeling creates opportunities for mix-ups, especially if you’re drawing multiple patients in sequence. A tube with the wrong patient’s blood inside, sometimes called a “wrong blood in tube” error, can lead to mismatched transfusions or wildly inaccurate test results.
An estimated 160,000 adverse patient events occur each year in the U.S. because of patient or specimen identification errors involving the laboratory. Eleven percent of all transfusion-related deaths happen because the phlebotomist didn’t properly identify the patient or mislabeled the tube. These aren’t abstract risks. They’re the reason every hospital enforces bedside labeling as a non-negotiable step.
Common Mistakes That Get Tubes Rejected
Labs reject blood specimens for a range of reasons, and labeling errors are among the most preventable. The main labeling problems that trigger rejection include:
- Unlabeled tubes: No label at all, which happens more often than you’d expect when a collector gets interrupted mid-draw.
- Mislabeled tubes: The label belongs to a different patient, or identifiers on the label don’t match the requisition form.
- Wrong medical record number: A single transposed digit can link results to the wrong patient chart.
- Illegible handwriting: If your facility still uses handwritten labels for any reason, unclear writing is grounds for rejection.
- Label on the cap instead of the tube: Caps get removed during processing. Any label on a lid or cap is effectively lost once the tube is opened.
Inadequately labeled samples account for roughly 5.6 to 6.7 percent of all rejected specimens. A large 2009 study found that blood bank samples specifically had a mislabeling rate of about 1.12 percent, which sounds small until you consider the volume of tubes a busy hospital processes daily. Even a fraction of a percent translates to real errors affecting real patients every week.
Printed Labels vs. Handwritten Labels
Printed labels generated from the electronic health record are the standard in most hospitals and large clinics. They eliminate legibility issues and typically include a barcode that links the tube to the patient’s order in the lab information system. When you scan a printed label at the bedside using a handheld scanner, it creates a digital chain of custody from the moment of collection through final result reporting.
Handwritten labels still appear in some smaller clinics, urgent situations, or when printers malfunction. If you must handwrite a label, print clearly in permanent ink. Include the same identifiers you’d find on a printed label: full name, date of birth, medical record number, date, time, and your initials. Avoid abbreviations that could be misread. Even with barcoding technology becoming widespread, studies have found that wrong-blood-in-tube error rates stayed essentially unchanged between 2007 and 2015 despite barcode scanner usage jumping from 8 percent to 38 percent. Technology helps, but it doesn’t replace careful manual verification.
Labeling Small Tubes and Microtainers
Capillary collection tubes and microtainers, the tiny tubes used for pediatric draws and fingerstick collections, present a practical challenge: standard labels are often wider than the tube itself. The solution is a “flag” technique. Wrap the label around the tube as far as it will go, then let the remaining portion of the label extend outward like a small flag. Some manufacturers sell label extenders, which are small sleeves or wings that attach to the microtainer to give you more surface area for the label.
The same identification rules apply to small tubes. Two patient identifiers, labeled at the point of collection, with a viewing window if possible. Because microtainers hold so little blood, the lab needs to be able to see the fill level even more than with standard tubes, so try to keep at least a narrow strip of the tube visible.
Double-Checking Before You Walk Away
Before leaving the patient, take five seconds to verify three things. First, confirm the name and date of birth on the label match the patient you just drew. Second, check that every tube from the draw is labeled, not just the first one. Third, make sure the label is smooth, firmly adhered, and not peeling at the edges. A label that falls off in a pneumatic tube system or transport bag becomes an unlabeled specimen, and the lab will reject it regardless of what was written on it.
If you realize after leaving the room that a tube is unlabeled or mislabeled, most facility policies require you to discard the specimen and redraw. You cannot label a tube from memory or based on what you think is correct. The integrity of the identification depends on the label being applied in the patient’s presence.