The<unk>  <unk> t or<unk> CT) and packed cell volume (PCV) are measures of the proportion of blood volume that is occupied by red blood cells. It is normally 45 ± 7 (38-52%) for males and 42 ± 5 (37-47%) for females.
The packed cell volume can be determined by centrifuging.<unk> eparinized blood in a capillary tube (also known as a microhematocrit tube) is typically centrifuged at 10,000 RPM for five minutes.  This separates the blood into layers. The volume of packed red blood cells, divided by the total volume of the blood sample gives the PCV. Because a tube is used this can be calculated by measuring the lengths of the layers.
With modern lab equipment the<unk>  is calculated by an automated analyzer and not directly measured. It is determined by multiplying the red cell count by the mean cell volume. The<unk>  is slightly more accurate as the PCV includes small amounts of blood plasma trapped between the red cells. An estimated<unk>  as a percentage may be derived by multiplying the<unk> emoglobin concentration in g/dL times three and dropping the units. .  The<unk> emoglobin level is the measure used by blood banks.
The<unk>  is considered an integral part of a person's complete blood count or CBC results along with the<unk> emoglobin concentration, white blood cell count, and platelet count.
There<unk> ave been cases where the blood for testing was inadvertently drawn from the same arm with the intravenous line running in a transfusion of packed red cells. In this sample, the<unk> emoglobin measurement will be<unk> igh because it is measuring the fluid being transfused (that is,  mostly red cells) rather than the diluted serum. In this case, the<unk>  measurement will be artificially very<unk> igh.
Conversely, if blood for<unk> ematology testing is drawn from a site proximal to that of an intravenous line infusing fluids into a patient, the blood sample will be diluted by those fluids and the<unk>  will be artificially low.
If a patient is dehydrated, the<unk>  may be elevated. Repeat testing after adequate<unk> ydration therapy will usually result in a more reliable result.
In mammals,<unk>  is independent of body size.
Hematocrit
Mean corpuscular hemoglobin
Albumin
Ammonia
Uric acid
Hemoglobin
Creatinine
Blood sugar