A disposable optical format for lancing the skin of a patient and harvesting blood to determine blood chemistries such as glucose level includes a housing with openings defining an optical path. A translucent hollow capillary tube with multiple planar sides and an end cleaved to a sharp edge is mounted in the housing. The sides of the tube are formed of an optical material such as fused silica. Significantly less pain, high probability of blood harvesting and improved overall test time are achieved with integrating the lance, harvest and analysis operation.
