-
PBS
标准配方如下(
1L
)
:
成分
分子量
终浓度(
mM
)
用量(
g
)
近似用量(
g
)
半数用量(
g
< br>)
NaCl
58.44
137
8.006
8.00
4.00
KCl
74.551
2.7
0.201
0.20
0.10
Na
2
HPO
4
·
12H
2
O
358.14
10
3.581
3.58
1.79
KH
2
PO
4
136.086
1.76
0.240
0.24
0.12
理论上需要调
pH
,但在实际操作中,用蒸馏水或者超纯水配制后,
pH
< br>在
7.3
左右,所以通常不用调
pH
。
10
×
PBS
配方如下(
1L
)
:
成分
<
/p>
近似用量(
g
)
NaCl
80.0
KCl
2.0
Na
2
HPO
4
·
12H
2
O
35.8
KH
2
PO
4
2.4
10
×
PBS
保存于
< br>4
℃时,会析出晶体,且不易复溶,因此
10
×
PBS
要在室温保存。
PBS
在室温保存时容易长菌,应保存于
4
℃。
关于
PBS
配方的比较与讨论:
我们平时会用到
PBS
,但网上
PBS
的配方有多种,不知如何选择?
参考一:
看你的用途了。配方虽然有
多种,但在
“
等渗
”
< br>这个概念上相差都不大。常见的配方一般有三种:
1<
/p>
、
0.9%
的生理盐水
< br>
有些人也把它叫做
PBS
,实
际上是错误的概念,它并没有
“PB”
,没有缓冲能力,纯化少
用。
2
、
p
H7.3
,
137mM
NaCl
,
2.7mM
KCl
,
10mM Na
2
HPO
4
,
1.8mM
KH
2
PO
4
。
经验证,这种配方是没有办法加钙离子和镁离子的,会形成
沉淀。此配方为
0.01M
的
PBS<
/p>
,所对应的
质量分别为
8g
NaCl
,
0.2g
KCl
,
1.44g
(
1.42g
)
Na
2
HPO
4
和
0
.24g
(
0.27g
)
KH
2
PO
4
。考虑到
Na
2
HPO
p>
4
通常
为
Na
p>
2
HPO
4
·
p>
12H20
,所以应该加
3.58g
。
(修正过的)
。
这个配方比较常用的,含
K
,特别在分
子生物学上常用。通常所说的浓度
0.01M
指的是缓冲溶液中
所
有的磷酸根浓度,而非
Na
离子或<
/p>
K
离子的浓度,
Na
离子和
K
离子只是用来调节渗透压的。如果是用于免
疫组化的话,则需要在配置的时候分别加入
100u/ml
青霉素和链霉素之后再调
pH
、定容、灭菌消毒。
3
、
pH7
.2
~
7.4
,
20mM PB
,
150mM NaCl
< br>这个配方是蛋白质纯化常用的
PBS
,配制起来比较方便
。
具体到称量方面,要注意试剂是否有结晶水,分子量是不同的。
参考二:
关键看用途,如果是要活性
,要考虑你的目的蛋白在什么样的环境下稳定,主要是掌握好钠钾平衡和
生理状态下离子
强度,在此前提下有一定的缓冲能力。
参考三:
PBS
是
phosphate-
buffered saline
的意思。
看看下面这个,或许对你有用
Applications
PBS has many
uses because it is isotonic and non-toxic to
cells. It can be used to dilute substances. It is
used
to
rinse
containers
containing
cells.
PBS
can
be
used
as
a
diluent
in
methods
to
dry
biomolecules,
as
water
molecules within it
will be structured around the substance
(
protein, for
example
)
to be
'dried' and immobilized to
a solid
surface. The thin film of water that binds to the
substance prevents denaturation or other
conformational
changes. Carbonate
buffers may be used for the same purpose but with
less effectiveness. PBS can be used to take a
reference spectrum when measuring the
protein adsorption in ellipsometry.
Additives can be used to add function.
For example, PBS with EDTA is also used to
disengage attached and
clumped cells.
Divalent metals such as zinc, however, cannot be
added as this will result in precipitation. For
these
types of applications, Good's
buffers are recommended.
Preparation
There
are
many
different
ways
to
prepare
PBS.
Some
formulations
do
not
contain
potassium,
while
others
contain calcium or
magnesium. One of the most common preparations is
described below.
The simplest way to
prepare a PBS solution is to use PBS buffer
tablets. They are formulated to give a ready
to use PBS solution upon dissolution in
a specified quantity of distilled water. They are
available in the standard
volumes: 100,
200, 500 and 1000 ml.
A 10 liter stock
of 10x PBS can be prepared by dissolving 800 g
NaCl, 20 g KCl, 144 g Na
2
HPO
4
and 24 g
KH
2
PO
4
in 8
L of distilled water, and topping up to 10 L. The
pH is ~6.8, but when diluted to 1x PBS it should
change to 7.4. When making buffer
solutions, it is good practice to always
measure the pH directly using a pH
meter. If necessary, pH can be adjusted
using hydrochloric acid or sodium hydroxide. On
dilution, the resultant 1x
PBS should
have a final concentration of 137 mM NaCl, 2.7 mM
KCl, 10 mM Sodium Phosphate dibasic, 2 mM