Sample Preparation

Question 1

What are the 7 steps involved in SEM sample preparation?

Answer 1

1.Sample collection 2.Fixation 3.Dehydration 4.Drying 5.Mounting 6.Coating 7.Examination

Question 2

What are 3 specimen drying methods?

Answer 2

Air drying, critical point dry (CPD), freeze dry

Question 3

What are 3 reasons why we fix biological samples?

Answer 3

1.Stabilize structure 2.Halt autolytic processes 3.Protect tissue from damage by the electron beam

Question 4

Define “critical point”

Answer 4

Temperature/pressure combination specific for the transitional fluid at which point a transition occurs and the density of the liquid phase equals that of the vapor phase

Question 5

What are 3 reasons why we coat most biological samples?

Answer 5

1.Prevents charging 2.Good source of secondary electrons 3.Conducts heat away from the specimen