<Table> <Tr> <Td> </Td> <Td> This article needs attention from an expert in biology . Please add a reason or a talk parameter to this template to explain the issue with the article . WikiProject Biology may be able to help recruit an expert . (May 2008) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article needs attention from an expert in biology . Please add a reason or a talk parameter to this template to explain the issue with the article . WikiProject Biology may be able to help recruit an expert . (May 2008) </Td> </Tr> <P> Rouleaux (singular is rouleau) are stacks or aggregations of red blood cells (RBCs) which form because of the unique discoid shape of the cells in vertebrates . The flat surface of the discoid RBCs gives them a large surface area to make contact with and stick to each other; thus forming a rouleau . They occur when the plasma protein concentration is high, and because of them the ESR (erythrocyte sedimentation rate) is also increased . This is a non-specific indicator of the presence of disease . </P>

An aid for dealing with a sample that has rouleaux in a hematology laboratory is to