Actinic keratoses that develop on the lips are referred to as actinic cheilitis. The clinical appearance of an actinic keratosis is that of a small (several millimeters), red scaly papule or plaque, with induration and thickening of the epidermis.
1 Location: Ideally, the probe should be in close proximity to the forward or reverse primer, but should not overlap with a primer-binding site on the same strand. 2  Probes can be designed to bind to either strand of the target. 3  Melting temperature (Tm): Preferably, probes should have a Tm 6â8Â°C higher than the primers.
The probe cross section can be distorted to form an ellipse, due to a range of factors such as level of machining accuracy and the material of the pole-piece, imperfections in the casting of the iron magnets and the copper winding. This distortion is called astigmatism and causes focus difficulties. Bad or gross astigmatism can be seen as streaking in the image in an X direction that changes to the Y direction as the image passes through focus from under focus to over focus.