Alternative inks for arbuscular mycorrhizal root staining

Alternative methods for arbuscular mycorrhizal (AM) fungal colonized root staining have recently gained more attention for the reduction of hazard exposure to the user. Sheaffer blue ink has been employed for such an identification and quantification, having shown an increased degree of image clarity. However, sourcing Sheaffer blue ink is becoming problematic, leading to the need to find alternative inks that are readily available. Parker ink is a well-known brand, providing comparable colour options to Sheaffer. Two Parker inks, blue and washable blue, were employed alongside Sheaffer blue for comparative AM fungal colonized root staining. From quantified AM fungal vesicles and arbuscles, along with the degree of stained image clarity under microscopy, none of the inks utilized for this comparison produce a significantly (P=0.97) different AM fungal quantification or change in image clarity. Therefore, the results of the present communication suggest that Parker blue and washable blue inks are alternative ink stains for the viewing and quantification of AM fungi in host cortical root tissues.