An automated staining apparatus for processing at least one biological sample arranged on a slide , the apparatus comprising: at least one capillary staining module (100, 100' 100") configured to hold a slide rack configured to hold one or more slides , and a capillary lid rack configured to hold one or more capillary lids ; and a first fluid container comprising a first fluid ; wherein the automated staining apparatus is configured to automatically: rotate the one or more slides from an insert position to one or more inclined position; position the one or more capillary lids towards the one or more slides to automatically form a capillary gap between each slide and each capillary lid , said capillary gap functioning as a capillary chamber; and to automatically supply an amount of the first fluid from the fluid container to the slide when in said inclined position; wherein the slide rack can be removed independently of removing the capillary lid rack and/or the automated staining apparatus is configured to automatically move one or more capillary lids back and forth in a direction parallel with the one or more sample slides , whereby local depletion of the fluid in the capillary gap is avoided and/or the fluid in the capillary gap is mixed. at least one capillary staining module (100, 100' 100") configured to hold a slide rack configured to hold one or more slides , and a capillary lid rack configured to hold one or more capillary lids ; and a first fluid container comprising a first fluid ; wherein the automated staining apparatus is configured to automatically: rotate the one or more slides from an insert position to one or more inclined position; position the one or more capillary lids towards the one or more slides to automatically form a capillary gap between each slide and each capillary lid , said capillary gap functioning as a capillary chamber; and to automatically supply an amount of the first fluid from the fluid container to the slide when in said inclined position; wherein the slide rack can be removed independently of removing the capillary lid rack and/or the automated staining apparatus is configured to automatically move one or more capillary lids back and forth in a direction parallel with the one or more sample slides , whereby local depletion of the fluid in the capillary gap is avoided and/or the fluid in the capillary gap is mixed. rotate the one or more slides from an insert position to one or more inclined position; position the one or more capillary lids towards the one or more slides to automatically form a capillary gap between each slide and each capillary lid , said capillary gap functioning as a capillary chamber; and to automatically supply an amount of the first fluid from the fluid container to the slide when in said inclined position; wherein the slide rack can be removed independently of removing the capillary lid rack and/or the automated staining apparatus is configured to automatically move one or more capillary lids back and forth in a direction parallel with the one or more sample slides , whereby local depletion of the fluid in the capillary gap is avoided and/or the fluid in the capillary gap is mixed. <EOS>