bio lab

• the process of adhering the bacterial cells to the microscope slide
• ensure that bacteria is not washed off during staining

important to make thin smear so that you clearly see the details of individual cells

small amount

spread across the whole slide

a process of adding a dye to a bacterial culture

releases sticky protein from the surface of the bacterial and adhere the bacteria cell to slide

positive charge

negative charge

slightly negative

• opposite attract
• if its the same charge the cell wont change color but the background will

uses one dye

uses at least 2 dyes

to view bacterial shape and arrangements

• bacillus cereus
• staphylococcus aureua
• klebsiella pneumoniae

methylane blue (basic dye)

gram + cocci

gram + bacilli

gram - bacilli

purple

red

• crystal violet
• gram iodine
• ethyl alcohol
• sefranin

• primary dye
• first dies applied
• stains gram positive purple

• mordant
• helps crystal violet sick to gram positive

increases attraction between the gram + cell wall and the crystal violet

• decolorizer of gram -
• turns it colorless

• counter dye
• cells decolorized by alcohol (gram-) will pick up the safranin turns it red