accuracy antigen check checking colloidal coronavirus covid-virus detection diagnosis diagnostic-aid dropper drops extraction-reagent-tube home-use immunochromatographic-technology kit limitations limited lysis-buffer measuring-instrument medical nasal nasal-secretion plastic quality-control-C-line rapid rectangular sample sampling-tube self-testing sterile-swab swab test test-cassette testing adansonia gregorii Australian baobab Australian boab boab boab tree bottle tree brown-gray brown-grey bush-tucker cut-open dead rat tree deciduous distinctive dried dried-out exterior food food-source fruit furry gadawon gouty stem tree hard indigenous Kimberley native large nut seed-pod shape shell slow-growing surface useful angles appearance arm background bits-and-pieces break breaking bricks broken builder builders claw debris deconstruction demolishing demolition disposable elements excavator external fractured fragments glass hydraulic hydraulics leftover light machine machines mechanical mortar old outside pieces rough rubbish rubble shadows Sizes sunlight texture textures tiles unwanted used waste worker workman Alley asphalt avenue back street burst bust up byway cobblestone concrete corrode corroded course crack cracked crossroad dragway drive flagstone flooring grunge in pieces kaput lane main drag open pavement pike puddle rain rainy road roadway rock route sidewalk stones stony street tar track trail water way wet barrel trunk cream flower flowers grotesque road verge smooth bark soft fibrous wood trunk verge water retention white