title: Quantification of platelets obtained by different centrifugation protocols in SHR rats.
abstract: OBJECTIVE
  To quantify the platelet concentration in the blood of SHR rats, by means of different centrifugation protocols, and to evaluate what the most effective method for obtaining platelets is.
  
  
  METHODS
  We used 40 male rats of the isogenic SHR lineage. The animals were divided into three groups: control, using whole blood without centrifugation; single centrifugation, using whole blood subjected to a single centrifugation at 200 × g and 400 × g; and double centrifugation, using whole blood subjected one centrifugation at different rotations, followed by collection of whole plasma subjected to another centrifugation at different rotations: 200 × g + 200 × g; 200 × g + 400 × g; 200 × g + 800 × g; 400 × g + 400 × g; 400 × g + 800 × g. Samples of 3 ml of blood were drawn from each animal by means of cardiac puncture. The blood was stored in Vacutainer collection tubes containing 3.2% sodium citrate. The blood from the control group animals was analyzed without being subjected to centrifugation. After the blood from the other groups of animals had been subjected to centrifugation, the whole plasma was collected and subjected to platelet counting in the lower third of the sample.
  
  
  RESULTS
  We obtained greatest platelet enrichment in the subgroup with two centrifugations comprising 400 × g for 10 min + 400 × g for 10 min, in which the mean platelet concentration was 11.30 times higher than that of the control group.
  
  
  CONCLUSIONS
  It was possible to obtain a high platelet concentration using viable simple techniques, by means of centrifugation of whole blood and use of commonly used materials. The most effective method for obtaining platelet concentrate was found in samples subjected to two centrifugations.
authors.affiliation: Universidade Federal de São Paulo (Unifesp), São Paulo, SP, Brazil.
authors.forename: João Alberto
authors.initials: JA
authors.lastname: Yazigi Junior
authors.affiliation: Universidade Federal de São Paulo (Unifesp), São Paulo, SP, Brazil.
authors.forename: João Baptista Gomes
authors.initials: JB
authors.lastname: Dos Santos
authors.affiliation: Universidade Federal de São Paulo (Unifesp), São Paulo, SP, Brazil.
authors.forename: Bruno Rodrigues
authors.initials: BR
authors.lastname: Xavier
authors.affiliation: Universidade Federal de São Paulo (Unifesp), São Paulo, SP, Brazil.
authors.forename: Marcela
authors.initials: M
authors.lastname: Fernandes
authors.affiliation: Universidade Federal de São Paulo (Unifesp), São Paulo, SP, Brazil.
authors.forename: Sandra Gomes
authors.initials: SG
authors.lastname: Valente
authors.affiliation: Universidade Federal de São Paulo (Unifesp), São Paulo, SP, Brazil.
authors.forename: Vilnei Mattiolli
authors.initials: VM
authors.lastname: Leite
keywords: Centrifugation; Platelet count; Platelet-rich plasma