buffers Flashcards
what do buffers do
maintain ph within a narrow range
why is it important to maintain ph
pH can change the structure of proteins which will change the function of proteins
what is immunohistochemistry
the process of visualizing a specific protein within tissue using an antibody that binds selectively to that protein and is conjugated to a flourophor or enzyme
what is pH
the negative log of the concentration of H+
important note about pH
the diffference of 1pH unit is a 10X difference of concentration of h3o+
how is a buffer made
when you mix a weak acid with its conjugate base
what is the buffer system that buffers blood pH
carbonic acid (H2CO3) and bicarbonate (HCO3-)
why do buffers work
there is an equilibrium between the acid (HA) and the conjucate base (A-) in solution
what effects pH
pKa and concentration of acid/base
what buffer system is used in your cells
phosphate buffer system
what makes up the phosphate buffer system used n your cells
dihydrogen phosphate (H2PO4) and hydrogen phosphate HPO42-
what is the pka of the phosphate buffer system
7.21
What is internal cell pH
6.9-7.4
What is the buffer system most commonly used for immunohistochemistry
phosphate buffered saline
what is the phosphate buffered saline used for in immunohistochemistry
washing tissue
how do we dilute the phosphate buffered saline
make a 10X stock solution and dilute it to 1X
what is a blocking buffer used for
to block non-specific binding of anibody to tissue. decreases background staining
what is in the blocking buffer
PBS buffer
bovine serum albumin(BSA) and carrageenan and Triton 100X
what is BSA
bovine serum albumin is a protein that wont give a signal. it binds to nonspecific protein binding sites
what is carrageenan
a polysaccharide that binds to nonspecific polysaccharide binding sites
what is triton 100
a detergent. it allows antibodies to pass through cell membranes to bind
what are the components of a pH meter
just go over this a couple times
