Colour of crystals in postive florence test is ?
Ans. is 'A' i.e., Dark brown Florence Test It is the chemical test for identification of semen in stains. The satin is extracted by 10% HCl and drop is placed on the glass slide and allowed to dry. A cover slip is placed over this and a drop of Florence solution (Potassium iodide, iodine and water) is allowed to run under the cover slip. If semen is present dark brown crystals of choline iodide appear immediately. They are rhombic or needle shaped crystals resembling haemin but are larger and arranged in clusters, rosettes, crosses etc. Choline originates from the seminal vesicles. Positive test is not a proof of seminal fluid, but only the presence of some vegetable or animal substance. A negative reaction is a proof that the stain is not seminal.
Yellow
White
Purple
Dark brown