Step 1: Describe the procedure for carrying out packed cell volume experiment. • Collect blood into a heparinized capillary tube, filling it to about two-thirds capacity. • Seal one end of the capillary tube with clay or by heating it in a flame. • Place the sealed tube into a microhematocrit centrifuge with the sealed end facing outwards. • Centrifuge the tubes at 10,000-12,000 rpm for 5 minutes. • Remove the tube and place it on a microhematocrit reader. Read the percentage of the packed red cell column relative to the total blood column. Step 2: Describe the procedures for collection of capillary blood. • Select a suitable site, typically the fingertip (ring or middle finger) for adults, or the heel for infants. • Cleanse the chosen site thoroughly with an alcohol swab and allow it to air dry completely. • Puncture the skin with a sterile lancet, making a quick, firm stab. • Wipe away the first drop of blood with a clean gauze pad, as it may contain tissue fluid. • Collect subsequent drops of blood into a capillary tube or onto a slide, avoiding excessive squeezing of the finger. • Apply gentle pressure with a clean gauze pad to the puncture site until bleeding stops. Step 3: Highlight the difference between the Ivy's and Duke's methods of bleeding time. • Ivy's Method: This method involves making a standardized incision (e.g., 1 mm deep, 10 mm long) on the forearm using a specialized device, while a blood pressure cuff is inflated to 40 mmHg on the upper arm to standardize venous pressure. It is considered more sensitive and reproducible. • Duke's Method: This method involves making a puncture on the earlobe or fingertip with a lancet. The depth of the puncture is less standardized, and no blood pressure cuff is used. It is less sensitive and less reproducible compared to the Ivy's method. Step 4: What are the factors that affects bleeding time? • Platelet Count: A low platelet count (thrombocytopenia) significantly prolongs bleeding time. • Platelet Function: Impaired platelet function, due to inherited disorders (e.g., Glanzmann's thrombasthenia, Bernard-Soulier syndrome) or medications (e.g., aspirin, NSAIDs), prolongs bleeding time. • Vascular Integrity: Defects in the blood vessel walls or surrounding connective tissue can lead to prolonged bleeding time. • Von Willebrand Factor: Deficiency or dysfunction of von Willebrand factor, which is crucial for platelet adhesion to the injured vessel wall, prolongs bleeding time. • Temperature: Extreme temperatures, particularly hypothermia, can impair platelet function and prolong bleeding time.