Tekeletso Bial ke teko ya motswako wa serayane wa pentose. Dikarolo di akaretsa orcinol, hydrochloric acid, le ferric chloride. Fa go tsentsweng pentose teng,pentose e tlabo e kgala go bopafurfural. Motswako yo otla bo o fetola mmala go nna botala jwa loapi le go bopa marothodi a pula. Motswako yo o supa karolo tse pedi tsa absorption bands, e ngwe fa gare ga B le C e nngwe fa gare ga mola wa D