erodz00

Hello all, I need help interpreting some observations we have made in our lab from gram stains taken of human lymphocyte cell products that are part of an immunotherapy clinical trial. In our lab we use the gram stain as a quick QC check of the samples before they are to be infused. If any bacterial cells (e.g. GNR or GPC) are observed, the material is rejected. I'm attaching some pics are reference. The first is what we normally observe (homogenous in color with apparent decolorization of crystal violet stain). However, recently we've been observing some darker cells amongst what we normally seen. In some cases, only a portion of the interior of the cells seems to retain the crystal violet stain. Could these be other types of cells? perhaps granulocytes? Improper staining? I'm also including a pic of a large cell that was observed that seems to be some sort of phagocytic cell. Any thoughts as to what this might be? All pics were taken at a 1000X magnification using a light microscope. In addition, our QC controls slides were acceptable in all of these tests. Thank you for your input!