# Children's sampling - Guide for children and parents In the laboratory, we take blood samples and conduct various types of studies on them. When examining the heart, we take an electrocardiogram, or an ECG. We will also be examining you, and all the tests we conduct are intended to treat you in the best way possible.  ## Welcome to the laboratory --- If you are ill, laboratory tests will help the doctor choose the types of treatments that will help you the best. The results of the laboratory tests will help us see if you are already better or still need treatment. If you are coming to the hospital for treatment or surgery, laboratory testing will help us plan your treatment correctly. ## What is blood? --- Have you ever had a wound so that it was bleeding? Blood is actually a substance called plasma, in which the different blood cells and platelets swim around. ## Red blood cells Most of the cells in blood are red blood cells and that is why blood is red in color. Red blood cells carry the air you breathe as “oxygen balls” and give strength to your muscles so you can move. ## White blood cells White blood cells are like detectives. They find all the bugs hiding in the human body. The white blood cell detectives capture and destroy the bacteria and viruses causing diseases. ## Platelets, or thrombocytes Platelets are busy repairing any wounds. Their task is to stop the wound from bleeding. If there are few platelets, it will take longer for the wound to stop bleeding. ## Blood sampling --- The sample collecting room has a chair where you can sit on the lap of your parent or caregiver when we take the blood samples. You can also sit in the chair by yourself. First, a sort of a belt will be placed around your arm and it will feel a bit tight. This will help make the blood vessel more visible in your arm. Next, your skin will be wiped with a disinfectant pad. The nurse will then draw a blood sample from your arm. It can pinch a little bit though. If necessary, another nurse can help you hold your arm in place. After the sampling, a piece of cotton pad and a band-aid will be placed on the injection site. You should press really tightly on top of the pad. > You don’t need to worry at all! > Sampling will be over quickly as long as you remember one really important thing: > You must keep your arm very still! Do not move it at all. ## Blood sampling from the fingertip --- A blood sample can sometimes also be taken from the fingertip. The hand is first warmed up for easy sampling. It is good if you sit quietly and stay very relaxed. The fingertip is wiped with a disinfectant pad and pricked very lightly. The droplets of blood are collected in small tubes. Finally, a nice band-aid is placed on your finger.  ## Magic band-aid --- Sometimes a numbing magic band-aid or some magic cream may be placed on your arm before sampling. The nice thing about the magic band-aid is that when you leave it on your arm for about an hour, you can almost not feel the sampling at all. It is not always possible to use a magic band-aid, but sampling even without a magic band-aid is just fine. Your guardian can ask for the magic band-aid from a pharmacy in advance. Once your blood samples are ready in the tubes, they will be sent for analysis. The laboratory examines even thousands of blood samples every day.  ## Electrocardiogram or ECG --- Sometimes the doctor wants to examine your heart. That’s when you will have an electrocardiogram or an ECG taken. It’s a pleasant examination, you can just lie down quietly for a moment and relax. First, the nurse will ask you to take off your shirt and socks. Then you can rest on the “elevator bed”, which can be lifted up and lowered down. The nurse will place nine adhesive electrodes on your chest. Similar electrode stickers are also placed on your wrists and ankles. When the electrodes are in place, the nurse will attach the wires on them. And then it is time for you to lie down comfortably like boiled spaghetti. During this, the ECG machine next to your bed will draw a curve from the beat of your heart. Now the electrocardiogram is done. If you want, the nurse can show you what your heart beat looks like when drawn by the computer. > We hope you’ve had a nice time reading about how a blood sample and ECG are taken. We will be happy to tell you more when you come to the laboratory. > > See you in the lab!  Likelihood to recommend (NPS) ## Diagnostic Center Feedback (pcs) 81310 Situation 2.5.2026 -100 88 100 i What is NPS? ## Further information on this topic ### [ Information for patients arriving for laboratory and medical imaging examinations ](/en/patient/treatments-and-examinations/laboratories-and-imaging/information-patients-arriving-laboratory-and-medical-imaging-examinations) This page has information on laboratory and imaging examinations and how to prepare for them. Links to the arrival and patient instructions are at the…  ### [ Laboratory tests ](/en/patient/treatments-and-examinations/laboratory-tests)  ### [ Laboratory booking and customer service ](/en/patient/treatments-and-examinations/laboratory-booking-and-customer-service)  ### [ Patient instructions laboratories and imaging ](/en/patient/treatments-and-examinations/patient-instructions-laboratories-and-imaging)  Updated: 06.10.2025 Print this page