Millonig’s Phosphate Buffer

Description

Millonig (1964); Karlsson and Schultz (1965)

Ingredients: Sodium Phosphate, monobasic (NaH2PO4xH2O) Sodium Phosphate, dibasic (Na2HPO4xH2O) 0.5% Sodium Chloride (NaCl)

Shipping Conditions: Ambient Temperature                     The pH of this buffer is 7.4 (0.1M);

Millonig’s prepare
1. Phosphate buffer (1961)
Sol A: 2.26% monobasic sodium phosphate in water
Sol B: 2.52% NaOH in water
Buffer final concentration: 0.13 M
Mix 41.5 ml of Sol A with 8.5 ml Sol B
Remove 5 ml of mix and add 5 ml of 4% sucrose solution.
Add 25g of MgCl2 or CaCl2 to each 100 ml of buffer
Adjust pH to 7.3 with Soln B
Stable for several weeks at 4 C
2. Phosphate buffer (1964)
In 500 ml dH2O:
Monobasic sodium phosphate 1.8 g
Dibasic sodium phosphate 23.25 g
NaCl 5 g
Ph to desired value then add
d H2O to make 1,000 ml

the osmolarity is 440 mosmols, so this buffer is hypertonic to most body fluids. Millonig recommended to use this buffer for the fixation of very hydrated tissues with osmium tetroxide. For marine organisms, a higher concentration of sodium chloride (3%) is recommended. We supply it in a double strength (0.2M), pH 7.4. Dilution is needed before use. Storage : 0-5°C MSDS_11582