An automated instrument for automatically processing a biological sample, comprising: (a) a rotatable platform capable of mixing a biological sample, wherein the platform rotates around a central axis; (b) two or more container holders (206, 208) arranged on the X-Y plane in spatially distinct locations on the rotatable platform, wherein the container holders are adapted to hold different shaped containers such that two or more different container holders are present; (c) a capping/decapping mechanism adapted to cap/decap the two or more different containers, wherein each of the two or more different containers have a different shape and/or a different shaped cap; (d) a data scanning mechanism capable of acquiring information about a container or its contents; (e) a robotic arm (112, 407, 408) incorporating an air-based pipettor system comprising a pipette tip, wherein the air-based pipettor system is adapted to aspirate sample from a container (102, 210, 211) containing a biological sample and dispense samples and reagents into reaction vessels characterized in that: the data scanning mechanism is arranged such that the container can be scanned while positioned in one of the two or more container holders; and in that it further comprises: (f) a mucoid strand detection mechanism adapted to detect a mucoid strand hanging from the pipette tip after the pipettor system aspirates sample from a sample container (102, 210, 211) and before the pipette tip has been moved away from the sample container, wherein the mucoid strand detection mechanism comprises machine vision, or reverse capacitive liquid level detection, or a combination thereof, and wherein the pipettor system is further adapted to fully dispense the sample back into the sample container (102, 210, 211) when a mucoid strand is detected by the mucoid strand detection mechanism. (a) a rotatable platform capable of mixing a biological sample, wherein the platform rotates around a central axis; (b) two or more container holders (206, 208) arranged on the X-Y plane in spatially distinct locations on the rotatable platform, wherein the container holders are adapted to hold different shaped containers such that two or more different container holders are present; (c) a capping/decapping mechanism adapted to cap/decap the two or more different containers, wherein each of the two or more different containers have a different shape and/or a different shaped cap; (d) a data scanning mechanism capable of acquiring information about a container or its contents; (e) a robotic arm (112, 407, 408) incorporating an air-based pipettor system comprising a pipette tip, wherein the air-based pipettor system is adapted to aspirate sample from a container (102, 210, 211) containing a biological sample and dispense samples and reagents into reaction vessels the data scanning mechanism is arranged such that the container can be scanned while positioned in one of the two or more container holders; and in that it further comprises: (f) a mucoid strand detection mechanism adapted to detect a mucoid strand hanging from the pipette tip after the pipettor system aspirates sample from a sample container (102, 210, 211) and before the pipette tip has been moved away from the sample container, wherein the mucoid strand detection mechanism comprises machine vision, or reverse capacitive liquid level detection, or a combination thereof, and wherein the pipettor system is further adapted to fully dispense the sample back into the sample container (102, 210, 211) when a mucoid strand is detected by the mucoid strand detection mechanism.