Abstract: The present invention relates to devices and methods for collecting liquid samples such as for removing a target liquid sample fraction from a larger liquid sample, e.g., from a biological sample. These devices and methods are particularly useful for rapidly and cost-effectively removing the buffy coat layer from an anticoagulated blood sample. These devices and methods have the advantage that the removal can be made on blood sample processed by ordinary centrifugation and do not require more complicated or costly processing techniques such as density gradient centrifugation.