Generally, decreases are seen in glucose and calcium
levels while phosphorus and potassium are increased in affected samples.7 Even though barrier gels separate blood cells from fluid components, they are capable of absorbing certain hormones and drugs, such as progesterone and phenobarbital.8 In addition, centrifuging samples using a fixed - head rotor centrifuge can allow gaps to develop in the gel barrier.4 This is
why it is recommended to separate serum and
plasma samples after centrifugation regardless of whether a separator gel is present in the tube.