Cell bio - LAB

Question 1

what is the picture formed in a microscope like?

Answer 1

from the physical aspect: uspide down, enlarged and virtual

biological aspect: DEPENDENT on the RATIO of ABSORPTION and TRANSMISSION of the loght

Question 2

what are the requirements of the LM sample?

Answer 2

colored
thin and transparent
PRESERVED (simulating the conditions in an alive organism)

Question 3

what is the first step of microtechnology?

Answer 3

the sample collection (drawing blood, section…)

Question 4

why do we do the fixation

Answer 4

to prevent autolysis. lysosomal enzymes start to self digest the tissue.

Question 5

what can we use as a physical fixative?

Answer 5

heat
microwaves
freezing (reversible) - go to method when in a rush
WE DO NOT USE THE UV LIGHT CUZ IT DESTROYS THE PROTEINS COMPLETELY

Question 6

what can we use as chemical fixators?

Answer 6

organic acids (VINEGAR)
HEAVY METAL SALTS
aldehydes (formaldehyde)
alcohol (removes the water)

Question 7

what are the most commom mistakes made while using chem fixatives?

Answer 7

when using organic acids - bulking of the specimen (cuz these acids attach water to themselves)
when using alcohol - dehydrating the specimen too much (alcohol removes the water)

Question 8

what is BOUIN composed of?

Answer 8

acetic acid, formaldehyde and picric acid

Question 9

what are the 2 ways of fixation

Answer 9

1. immersion (might lead to autolysis cuz the fixative cannot reach every cell soon enough)
2. perfusion - injecting the fixative in the animal bloodstream